E.  F.  Mahady  Co. 

Medical  Books, 

Boston. 


883 


Webster  Famiiy  Library  of  Veterinary  Medicin 
Cummings  School  of  Veterinary  Medicine  at 
Tufts  University 
200  Westboro  Road 


FRONTISPIECE 


Normal  Fundus  of  a  Dog's  Left  Eye. 


M.HOV, 


OPHTHALMOLOGY 

for 

VETERINARIANS 


BY 

WALTER  N.  SHARP.  M.D. 

PROFESSOR    OF    OPHTHALMOLOGY    IN   THE    INDIANA    VETERINARY 

COLLEGE  ;       OPHTHALMIC    SURGEON    TO    THE    INDIANAPOLIS    CITY 

HOSPITAL 


ILLUSTRATED 


PHILADELPHIA  AND  LONDON 

W.  B.  SAUNDERS  COMPANY 

1913 


^13 


Copyright,  1913,  by  W.  B.  Saunders  Company 


PRINTED    IN    AMERICA 

PRESS    OF 

W.     B.     SAUNDERS     COMPANy 

PHILADELPHIA 


DEDICATED  TO  THE  MEMORY  OF   MY  SON 

WILFRED    EMERSON    SHARP 

WHO  DEPARTED  THIS  LIFE 

SEPTEMBER  lo,   1904 
IN  HIS  EIGHTEENTH  YEAR 


PREFACE 


This  small  volume  is  the  fulfilment  of  a  wish  often 
expressed  by  the  students  of  the  Indiana  Veterinary 
College.  It  comprises,  with  the  exception  of  dissections 
and  clinical  demonstrations, .  the  work  with  the  senior 
class  in  this  department  during  the  term. 

As  external  diseases  of  the  eye  are  principally  seen 
in  animals,  more  attention  has  been  given  such  diseases 
in  as  plain  and  few  words  as  is  consistent  with  the  sub- 
ject, so  that  they  may  be  comprehended  by  the  student 
as  well  as  by  the  practitioner. 

I  am  indebted  to  Drs.  G.  H.  Robberts,  W.  B.  Craige, 
and  other  members  of  the  Indiana  Veterinary  College 
for  valuable  assistance,  and  to  Drs.  G.  E.  deSchweinitz, 
Alexander  Duane,  Wm.  C.  Posey,  and  other  authors  of 
works  on  ophthalmology  for  valuable  information. 

As  the  Hterature  upon  diseases  of  the  eye  in  animals 
is  extremely  Hmited,  I  have  been  obhged  to  draw 
largely  from  'Taw's  Veterinary  Medicine,"  especially 
on  the  subject  of  parasites  of  the  eye. 

Walter  N.  Sharp. 

Indianapolis,  Indiana, 
March,  1913- 

3 


CONTENTS 


CHAPTER  I  PAGE 

Anatomy  of  the  Eye 1 1 

Definition,   ii— Coats,    14— The  Eye  Internally,   14— The 

Sclera,  14— The  Chorioid,  15— The  Retina,  17— The  Cornea, 

.      20— The  Iris,  21— The  Pupils,  24— The  Ciliary  Body,  24— The 

Lens,    25— The    Vitreous,    26— The    Conjunctiva,    27— The 

Nictitans  IMembrane,  27. 

CHAPTER  II 

Systematic  Examination  of  the  Eye 29 

The  Lids,  29— The  Conjunctiva,  30— The  Cornea,  30— 
The  Pupils,  30— The  Iris,  31— The  Lens,  31— The  Tension,  32. 

CHAPTER  III 

Diseases  of  the  Lids 33 

General  Description  of  the  Lids,  33— Edema,  35— Emphy- 
sema, 35— Ecchymosis,  35— Burns,  35— Wounds,  36— Ectro- 
pion, 36— Entropion,  36— Lagophthalmus,  37— Ptosis,  37— 
Tarsitis,  37— Elephantiasis,  37— Blepharospasm,  38— Ankylo- 
blepharon, 38— Blepharitis  Marginalis,  38— Hordelum,  or  Stye, 
40— Chalazion,  40— Tumors  of  the  Eyelids,  41— Ulcers  of  the 
Lid,  42— Abscess  of  the  Lid,  42— Trichiasis,  43— Distichiasis,  44- 

CHAPTER  IV 

Operations  on  the  Lids 45 

Ectropion,  46— Entropion,  51— Trichiasis,  53— Ankylo- 
blepharon, 55 — Ptosis,  56. 

CHAPTER  V 

Diseases  of  the  Lacrimal  Apparatus 57 

Dacrocystitis,  57— Stenosis  of  the  Nasal  Duct,  58. 

5 


6  CONTENTS 

CHAPTER  VI 

Muscles  of  the  Eyeball 59 

Affections  of  the  Muscles,  6 1— Ophthalmoplegia,  62. 

CHAPTER   VH 

Diseases  of  the  Conjunctiva 64 

Conjunctivitis,  64— Acute  Catarrhal  Conjunctivitis,  64— 
Chronic  Conjunctivitis,  66— Purulent  Conjunctivitis,  68— 
Phlyctenular  Conjunctivitis,  71— Trachoma,  7  2— Follicular 
Conjunctivitis,  74— Xerosis,  75— Membranous  Conjunctivitis, 
^5_Pinguecula,  78— Tuberculosis  of  the  Conjunctiva,  79— 
Pterygium,  79— Foreign  Bodies  in  the  Conjunctiva  and 
Cornea,  80— Burns  of  the  Conjunctiva  and  Cornea,  83— 
Tumors  of  the  Conjunctiva,  84— Inflammation  of  the  Nicti- 
tans  Membrane,  86. 

CHAPTER  YIII 

Diseases  of  the  Cornea ^° 

Keratitis,  88— Ulcers  of  the  Cornea,  90— Pannus,  97— 
Phlyctenular  Keratitis,  99— Herpes  Corneae,  99— Dentritic 
Keratitis,  100 — Filamentous  Keratitis,  100 — Desiccation 
Keratitis,  loi — Neuroparalytic  Keratitis,  loi — Keratomala- 
cia,  or  Xerosis  of  the  Cornea,  102 — Staphyloma  of  the  Cornea, 
102 — Keratectasia,  105— Keratoconus,  or  Conic  Cornea,  105 — 
Keratoglobus,  105 — Opacities  of  the  Cornea,  106 — Interstitial 
Keratitis,  108. 

CHAPTER  IX 

Diseases  of  the  Iris  and  Ciliary  Body no 

Congenital  Defects,  1 11— Mydriasis,  in— Myosis,  in— 
Iritis,  112 — CycHtis,  114 — Cysts  and  Tumors  of  the  Iris,  119 — 
Tuberculosis  of  the  Iris,  120— Tumors  of  the  Iris  and  Ciliary 
Body,  121. 

CHAPTER  X 

Diseases  of  the  Retina  and  Chorioid 124 

Anemia,  127— Edema,  127— Hyperemia,  128— Hemor- 
rhages, 128— Detachment,  128— Retinitis,  128— Atrophy  of 
the  Retina,  129 — Rupture  of  the  Retina,  130 — Glioma,  130 — 
Diseases  of  the  Chorioid,  130— Purulent  Chorioiditis,  132. 


CONTENTS  7 

CHAPTER  XI 

PAGE 

Diseases  of  the  Optic  Nerve 133 

Papillitis,   133 — Retrobulbar  Neuritis,   134 — Toxic  Ambly- 
opia, 134 — Atrophy  of  the  Optic  Nerve,  135. 

CHAPTER  XII 

Diseases  of  the  Lens i37 

Cataract,  137^ — Luxation  of  the  Lens,  142 — Lenticonus,  143. 

CHAPTER  XIII 

Operations  for  Cataract i44 

Discission,  144 — Extraction,  145 — Iridectomy,  148 — Dress- 
ing, 151. 

CHAPTER  XIV 
Recurrent  Ophthalmia i5S 

CHAPTER  XV 

Glaucoma 158 

CHAPTER  XVI 

Injuries  of  the  Globe 162 

Contusions,  162— Punctures,  163— Lacerations,  164— Com- 
plications, 165— Treatment  of  Injuries  of  the  Globe,  166— 
Simple  Abrasions  of  the  Cornea,  166— Perforating  Wounds  of 
the  Cornea,  166— Injuries  of  the  Globe,  with  Foreign  Bodies 
Remaining  in  the  Eye,  168— Enucleation  of  the  Globe,  170— 
Prolapse  of  the  Eyeball,  172. 

CHAPTER  XVII 

Fracture  of  the  Orbit 1 74 

Treatment,  174. 

CHAPTER  XVIII 

Parasites  of  the  Eye 176 

Parasites  of  the  Eyehds,  176— Parasites  Found  Within  the 
Eyeball,  178. 

CHAPTER  XIX 

The  Principles  of  Vision iSi 

Refraction,  181— Spheric  and  Cylindric  Lenses,  182— Acuity 
of  Vision,  187— Accommodation,  188 — Fields,  192 — Scotoma, 
194. 


8  CONTENTS 

CHAPTER  XX  PAGE 

Errors  of  Refraction 195 

Hyperopia,  195 — Myopia,  195 — ^Astigmatism,  196 — Presby- 
opia, 197 — Emmetropia,  197 — Method  Used  to  Determine 
the  Refractive  Error,  197. 

CHAPTER  XXI 

Medicines  Used  in  Ophthalmic  Therapeutics 200 

Antiseptic  Washes,  200 — Astringents,  200 — Local  Anesthet- 
ics, 201 — Caustics,  201 — Mydriatics,  201 — Myotics,  201 — 
Lymphagogues,  201 — Hemostatics,  202 — Ointments,  202 — 
Powders,  202 — Combinations,  202. 


Index 203 


LIST  OF  ILLUSTRATIONS 


Normal  Fundus  of  a  Dog's  Left  Eye Fronthfiece 

PAGE 
FIGURE 

1 .  Portion  of  skull  of  horse,  showing  bony  orbit 12 

2.  Vertical  axial  section  of  orbit  of  horse i3 

3.  Vertical  section  of  eyeball  of  horse ^5 

4.  Vascular  tunic  of  eyeball  of  horse,  front  view 16 

5.  Fundus  oculi,  seen  on  equatorial  section  of  eyeball  of  horse ...  17 

6.  Vertical  section  of  anterior  part  of  eye  of  horse,  with  lids 

half  closed.... '^ 

7.  Iris  of  horse,  showing  position  of  the  corpora  nigra 22 

8      Eyeball  of  horse  in  orbit,  showing  shape  of  the  iris  and  cor- 

pora  nigra ^ 

9.     Knapp's  lid  clamp ^ ^^ 

10,11.     Wharton  Jones' operation  for  ectropion 46 

12^  13.     Kuhnt-Szymanowski  operation 47,  48 

14,  15.     Dieffenbach's  operation 5° 

16,  17.     Burow's  operation ^i 

18.     Operation  of  Anagnostakis  and  Hotz 52 

Cilium  forceps ^^ 

Canthoplasty ^^ 

...     Right  eye  of  horse ° 

22.  Dermoid  cyst  of  the  cornea 4 

23.  Staphyloma  of  the  cornea ^°^ 

24.  Protrusion  of  the  globes ^° 

25.  Carcinoma  of  the  orbit  of  dog ;•  "9 

26.  Carcinoma  of  the  orbit  of  cat ^"° 

27.  Sarcoma  of  the  orbit  of  horse ^ 21 

28.  Tumor  of  the  orbit ^^^ 

29.  ■  Melanosarcoma  of  the  chorioid ^^3 

30.  Loring's  ophthalmoscope -^ "5 

31.  Dislocation  of  the  lens ^42 

32.  Eye-protector  for  horse ^^2 

33.  Brusasco's  eye-protector  for  dog ^53 


lo  LIST  OF  ILLUSTRATIONS 


34.  Brusasco's  eye-protector  for  dog  applied 153 

35.  Injury  of  the  globe  of  horse 165 

36.  Enucleation  of  the  eye  of  horse 171 

37.  Principal  focus  of  a  convex  lens 182 

38.  Conjugate  focus  of  a  convex  lens 183 

39.  Virtual  focus  of  a  convex  lens 183 

40.  Principal  focus  of  a  concave  lens 184 

41.  Virtual  image  of  a  convex  lens 184 

42.  Virtual  image  of  a  concave  lens 185 

43.  Image  formed  by  a  convex  lens 185 

44.  Diagram  illustrating  the  visual  path  and  the  relation  of  the 

visual  field 192 


OPHTHALMOLOGY    FOR 
VETERINARIANS 


CHAPTER  I 
ANATOMY  OF  THE  EYE 
"From  a  point  of  view  of  comparative  anatomy,  an 
eye  is  any  part  of  an  animal  body  which  responds 
more  readily  than  other  parts  to  the  special  stimulus 
of  hght,  or  whose  activity  is  specially  excited  by  the 
impact  of  Hght  rays."— Cew/wry  Dictionary. 

In  the  low  forms  of  life  the  eye-spots  or  eye-points, 
as  they  are  called,  differ  greatly  in  number.  They 
are  rudimentary  eyes,  and  consist  in  many  cases  of 
simple  pigment  spots  sensitive  to  light,  and  may  be 
situated  anywhere  on  the  body. 

In  insects  proper,  crustaceans  and  arachnidians,  the 
eyes  are  well  developed  and  are  either  simple  or  com- 
pound. They  are  usually  two  in  number,  but  may  be 
four,  six,  or  eight.  Crustaceans,  as  a  rule,  have  a  single 
pair,  which  stand  out  from  the  head  like  a  cherry  upon 
a  stem. 

In  describing  the  anatomy  of  the  eye,  that  of  the 
highest  order  of  the  animal  kingdom  will  be  consid- 


11 


12  OPHTHALMOLOGY  FOR  VETERINARIANS 

ered.  The  higher  in  the  scale  of  animal  hfe,  the  more 
nearly  is  the  eye  like  that  of  man;  the  only  difference 
is  the  addition  of  some  conveniences  of  which  man  is 
not  in  need.  Most  of  the  quadrupeds,  for  instance, 
are  supplied  with  a  third  eyeUd,  or  nictitans  mem- 
brane, and  a  retractor  muscle.     The  former  acts  as  a 


Fig.  I. — Portion  of  skull  of  horse,  showing  bony  orbit. 

finger  to  remove  foreign  bodies,  dust,  etc.,  that  may 
fall  upon  the  cornea.  The  latter  serves  to  draw  the 
eyeball  backward  into  the  orbit  and  protect  it  from 
approaching  harm.  These,  together  with  the  varia- 
tions in  size,  are  the  only  practical  differences  from  the 
human  eye. 

The    eyes   of    quadrupeds   present   nearly   laterally, 


ANATOMY  OF  THE  EYE 


13 


and  are  protected  by  bony  orbits  and  soft  appendages. 
They  are  embedded  in  a  cushion  of  fat  and  surrounded 


Fig.  2.— Vertical  axial  section  of  orbit  of  horse:  a,  a,  Eyelids;  b,  bulbar 
fascia  (Tenon's  capsule);  c,  c',  retractor  bulbi;  d,  rectus  oculi  inferior; 
e,  obliquus  oculi  inferior  (in  cross-section);  /,  rectus  oculi  superior;  g, 
levator  palpebrce  superioris;  h,  obliquus  oculi  superior  (in  cross-section); 
i,  lacrimal  gland;  k,  k',  periorbita;  /,  superficial  fascia;  m,  deep  fascia;  n, 
skin;  0,  retrobulbar  fat;  p,  extra-orbital  fat;  q,  temporalis  muscle;  r,  supra- 
orbital process;  s,  cranial  wall;  i,  cornea;  2,  sclera;  3,  choroidea;  4,  ciliary 
muscle;  5,  iris;  6,  granula  iridis;  7,  retina;  f,  optic  papilla;  8,  optic  nerve; 
p,  crystalline  lens;  10,  capsule  of  lens;  11,  ciliary  zone;  12,  posterior  cham- 
ber; 13,  anterior  chamber;  14,  conjunctiva  bulbi;  ij,  vitreous  body. 
(After  Ellenberger,  in  Leisering's  x\tlas.) 

or,  rather,  encased  within  a  capsule,  in  which  they  are 
freely  moved  at  will  by  the  aid  of  the  extrinsic  muscles. 


14  OPHTHALMOLOGY  FOR  VETERINARIANS 

The  coats  of  the  posterior  five-sixths  of  the  globe  are 
three  in  number,  and  from  without  inward  are  called 
the  sclera,  the  chorioid,  and  the  retina.  The  anterior 
one-sixth  is  formed  by  the  transparent  cornea. 

The  eye  internally  is  composed  of  the  anterior  cham- 
ber, the  iris  and  cihary  body,  the  posterior  chamber, 
the  lens  in  its  capsule  suspended  by  the  cihary  liga- 
ment from  the  ciHary  muscle,  the  vitreous  encased  in 
the  hyaloid  membrane,  and  the  optic  disk. 

The  sclera  is  a  white,  tough,  fibrous  membrane, 
and  extends  from  the  optic  nerve  to  the  cornea.  It 
is  really  an  expansion  of  the  dura  mater,  which  ^tends 
forward  from  the  skull  cavity  through  the  optic  foramen 
in  the  apex  of  the  orbit,  and  serves,  in  its  course  to  the 
eyeball,  as  a  sheath  for  the  optic  nerve.  It.  is  principally 
for  protection,  and  affords  attachment  for  the  extrinsic 
muscles.  The  four  recti  and  the  two  oblique  muscles 
have  their  attachment  anterior  to  the  equator,  while 
the  retractor  muscle  is  widely  expanded  over  the  poste- 
rior third  of  the  sclera,  which  is  its  thickest  portion. 

The  fine  fibrillae  of  which  the  sclera  is  composed  run 
in  two  principal  directions — from  before  backward,  and 
in  a  circular  direction  concentric  with  the  corneal 
margin. 

Anteriorly,  the  sclera  is  continuous  with  the  true  cor- 
nea. At  the  posterior  portion  a  few  fibers  of  the  inner 
layer  penetrate  the  optic  nerve  at  a  junction  with  the 
trunk  of  the  nerve  and  its  head,  and  are  inserted  into 


ANATOMY  OF  THE  EYE 


15 


the  connective  tissue  about  the  central  vessels.  This 
portion  is  known  as  the  lamina  cribrosa.  The  deep  lay- 
ers of  the  sclera  contain  numerous  pigment-cells,  more 
pronounced  in  animals  than  in  man,  hence  the  brown- 
ish or  bluish  color.    It  is  penetrated  by  numerous  cihary 


Anterior 
chamber 


Rectus  oculi  inferior 


Ciliary 
processes 

Chorioid 

Y{g,  3.— Vertical  section  of  eyeball  of  horse,  about  f .     The  contour  of  the 

crystalline  lens  is  dotted.     (Sisson,  Veterinary  Anatomy.) 

vessels  at  the  posterior  portion  surrounding  the  optic 
nerve  entrance.  The  anterior  portion  is  connected  to 
the  conjunctiva  by  a  loose  connective  tissue,  known 
as  the  episcleral  tissue. 

The  chorioid,  or  middle  coat,  is  a  vascular  and  pig- 


i6 


OPHTHALMOLOGY  FOR  VETERINARIANS 


mentary  structure.  Its  function  is  to  nourish  the  eye 
and  absorb  Hght.  It  extends  from  the  optic  disk  to  the 
ora  serrata. 

Histologically,   the  chorioid   consists   of  five  layers. 
First,    from    without    inward,    the    suprachorioid,  inti- 


Fig.  4. — Vascular  tunic  of  eyeball  of  horse,  front  view.  The  cornea 
is  removed  and  the  sclera  is  reflected  in  flaps:  i,  Sclera;  i',  lamina  fusca; 
2,  choroidea;  2',  ciliary  veins;  j,  ciliary  muscle;  4,  iris;  5,  5',  granula 
iridis;  6,  pupil,  through  which  the  lens  is  visible.  (After  Ellenberger,  in 
Leisering's  Atlas.) 

mately  connecting  it  with  the  sclera;  second  and  third, 
are  two  layers  of  vessels,  large  and  small  respectively, 
embedded  in  a  stroma  of  connective  tissue  with  numer- 
ous branched  pigment- cells;  fourth,  the  lamina  ruyschii, 


ANATOMY  OF  THE  EYE  17 

composed  principally  of  capillaries;  fifth,  the  lamina 
vitrea,  which  is  lined  with  a  layer  of  pigment  epithe- 
lium. Late  authorities  claim  that  this  pigment-layer 
embryologically  belongs  to  the  retina.  An  absence  of 
black  pigment  on  the  posterior  layer  in  the  carnivora 
affords   a   greenish-blue   reflex,    and   is   known   as   the 


Fig.  5. — Fundus  oculi,  seen  on  equatorial  section  of  eyeball  of  horse: 
I,  Sclera;  2,  choroidea;  j,  retina  (loosened);  4,  tapetum;  5,  optic  papilla; 
6,  optic  nerve.     (After  Ellenberger,  in  Leisering's  Atlas.) 

''tapetum  lucidum."  This  reflex  is  noticeable  in  cats' 
eyes  in  the  dark. 

Because  of  the  intimate  association  of  the  pigment 
and  circulatory  layers  of  this  body  with  those  of  the 
ciliary  body  and  iris,  and  from  the  likeness,  as  a  whole, 
to  that  of  a  grape  when  the  sclera  is  stripped  off,  this 
portion  of  the  eye — the  iris,  the  ciliary  body,  and  the 
chorioid — is  known  as  the  uveal  tract  or  uvea. 

The  retina  is  the  internal  coat  or  lining  of  the  eye. 


1 8  OPHTHALMOLOGY  FOR  VETERINARIANS 

It  is  composed  principally  of  nerve  elements  and  is 
practically  an  expansion  of  the  optic  nerve.  Its  function 
is  to  receive  the  image  focused  by  the  refractive  media, 
which  is  conveyed  through  the  optic  nerve  to  the  sight 
center  in  the  occipital  lobes.  The  retina  of  the  living 
eye  is  transparent,  while  that  of  the  dead  eye  is  opaque. 
It  also  loses  its  transparency  in  portions  undergoing 
pathologic  changes. 

It  extends  posteriorly  from  the  optic  nerve,  and  ap- 
parently terminates  anteriorly  at  an  irregular  Hne, 
known  as  the  ora  serrata,  posterior  to  the  apex  of  the 
cihary  body,  but  ''the  microscope  shows  that  under 
a  similar  form  it  extends  still  farther,  even  up  to  the 
edge  of  the  pupil.  It,  therefore.  Hues  the  inner  surface 
of  the  cihary  body  and  the  posterior  surface  of  the 
iris'^  (Fuchs). 

Corresponding  with  the  central  vision  at  the  poste- 
rior pole  hes  a  small  yellowish  spot,  called  the  macula 
lutea,  a  slight  depression  in  the  center  of  which  is  the 
fovea  centralis. 

Histologically,  the  retina  is  a  very  complicated 
structure,  and  consists  from  without  inward  of  ten 
layers:  i,  A  pigment  epithelial  layer;  2,  a  layer  of  rods 
and  cones;  3,  an  external  limiting  membrane;  4,  an 
external  molecular  layer;  5,  an  external  granular  layer; 
6,  an  internal  molecular  layer;  7,  an  internal  granular 
layer;  8,  a  layer  of  granular  cells;  9,  a  layer  of  nerve- 
fibers;    10,    an   internal   limiting   layer   or   membrane. 


ANATOMY  OF  THE  EYE 


19 


n  3 

Fig  6 -Vertical  section  of  anterior  part  of  eye  o(  horse,  with  hds 
half  closed:  I,  Tarsal  gland  of  upper  lid;  .,  palpebral  conjunctiva;  3, 
fornix  conjunctiva.;  4,  levator  palpebrce  superioris;  5,  orb.culans  ocuh 
6  cornea;  7,  anterior  chamber;  8,  iris;  p,  p',  granula  ind.s;  10.  posterior 
chamber;  u,  ciliary  process;  i.,  ciliary  muscle;  13,  cd.ary  zone  or  sus- 
pensory ligament  of  lens;  i^.chorioid;  15,  sclera;  16,  lens;  17,  root  of 
tactile  hair.     (After  Bayer,  Augenheilkunde.) 

The  pigment  epithelial  layer  is  the  one  before  men- 
tioned with  the  chorioid,  which  really  belongs  to  the 
retina.    The  rods  and  cones  are  unevenly  distributed, 


20  OPHTHALMOLOGY  FOR  VETERINARIANS 

as  the  cones  only  exist  in  the  fovea,  while  the  rods 
become  more  abundant  from  the  border  of  the  macula 
lutea  to  the  ora  serrata,  while  the  cones  diminish. 

The  retinal  vessels  enter  through  the  center  of  the 
optic  nerve,  expanding  and  dividing,  much  Hke  the  twigs 
of  a  tree,  through  the  retinal  tissue  to  the  ora  serrata 
without  anastomosing.  These  afford  nourishment  to 
the  inner  layers,  while  the  outer  layers  are  dependent 
upon  the  small  vessels  of  the  inner  layer  of  the  chorioid 
for  nourishment.  The  retinal  vessels  can  be  distinctly 
seen  by  the  aid  of  the  ophthalmoscope. 

The  cornea  comprises  about  one-sixth  of  the  ex- 
ternal anterior  portion  of  the  eyeball.  It  is  a  perfectly 
transparent  body,  and  one  of  the  refractive  media  next 
in  importance  to  the  lens.  The  anterior  surface  is  con- 
vex and  the  posterior  is  concave. 

It  is  composed  of  five  layers.  From  without  inward, 
they  are:  The  epithelial  layer,  Bowman's  membrane, 
the  stroma  or  cornea  proper,  Descemet's  membrane, 
and  the  endothelium.  The  epithelium  is  composed  of 
columna,  polyhedral  and  squamous  cells,  and  is  con- 
tinuous with  the  conjunctiva.  Bowman's  membrane 
is  devoid  of  cells,  and  is  described  as  an  elastic  homo- 
geneous membrane.  It  is  strongly  adherent  to  the 
stroma.  The  stroma  is  the  thickest  layer,  and  con- 
sists of  numerous  fibrous  layers  enclosing  corpuscles 
similar  in  structure  closely  connected  by  a  cement 
substance.     The   corneal   cells   proper   are   fixed   non- 


ANATOMY  OF  THE  EYE  21 

motile  cells,  flat  in  appearance,  and  connected  to 
neighboring  cells  by  branched  processes.  A  type  of 
motile  cell,  said  to  be  white  blood-corpuscles,  but  few 
in  number,  float  in  the  lymph-channels  of  the  stroma. 
This  portion  of  the  cornea  is  continuous  with  the  sclera. 
Descemet's  membrane  is  an  elastic  homogeneous  hya- 
loid membrane,  and  is  easily  separated  from  the  stroma. 
.It  is  said  to  be  the  protecting  membrane  of  the  poste- 
rior portion  of  the  cornea  because  of  its  elasticity  and 
resistance  to  pathologic  processes.  The  endothelium 
or  posterior  epithelium,  as  it  is  sometimes  called,  lines 
the  posterior  portion  of  Descemet's  membrane.  It 
is  composed  of  flattened  cells  of  a  single  layer. 

The  cornea  has  no  vessels  of  its  own,  but  is  nourished 
by  a  network  of  capillary  loops  near  the  border.  These 
loops  are  supplied  by  the  anterior  ciliary  vessels. 

The  iris  is  practically  a  diaphragm,  much  like  the 
diaphragm  in  a  camera,  with  an  opening  in  the  center 
called  the  pupil.  It  is  a  dividing  membrane  between  the 
anterior  and  the  posterior  chambers,  which  are  filled 
with  a  watery  fluid  known  as  the  aqueous  humor. 
The  pupillary  portion  of  the  iris  rides  on  the  lens  dur- 
ing contraction  and  dilatation.  By  reason  of  the  con- 
vexity of  the  lens  the  iris  is  sHghtly  pushed  forward 
at  this  portion.  Should  the  lens  be  absorbed,  dislocated, 
or  removed,  the  iris  would  be  tremulous  for  want  of 
support.    This  is  known  as  iridodonesis. 

The   iris    arises    from   the    anterior    portion   of    the 


22  OPHTHALMOLOGY  FOR  VETERINARL\NS 

ciliary  body  also  by  a  ligament  of  loose  tissue  from  near 
the  posterior  portion  of  the  sclerocorneal  connection. 
This  Hgament  is  called  the  hgamentum  pectinatum. 
It  has  nearly  a  semicircular  shape,  and  comprises  the 
angle  between  the  sclerocorneal  margin  and  the  iris. 
It  is  the  extreme  boundary  of  the  anterior  chamber 
and  a  most  important  structure. 

The  iris  is  described  as  ''a  spongy  sort  of  tissue/' 
composed    principally    of    numerous    delicate    blood- 


Fig.  7. — Iris  of  the  horse,  showing  position  of  corpora  nigra. 

vessels,  radiating  from  the  periphery  toward  the  pupil, 
and  interspersed  with  a  meshwork  of  branched  and 
pigment-cells.  The  anterior  surface  is  covered  with 
epithelium  (except  the  hollow  spaces  or  crypts),  which 
is  continuous  with  that  on  the  posterior  cornea.  The 
posterior  surface  is  covered  with  a  delicate  membrane, 
upon  which  rests  a  layer  of  pigment  epithelium.  This 
membrane,  with  its  fibers  extending  in  a  radial  direc- 
tion,   constitutes    the    dilator    pupillae    muscle.      The 


ANATOMY  OF  THE  EYE  23 

sphincter  pupilte  is  a  circular,  flat  body,  located  in  the 
stroma  near  the  pupillary  margin.  This  muscle  con- 
tracts the  pupil. 

The  posterior  layer  of  pigment  epithelium  is  con- 
tinuous with  that  of  the  ciliary  body  and  retina.    It 


./ 


^ 


Fig.  8.-Eyeb.U  of  horse  in  orbit,  slrowing  shape  of  the  iris  and  the  corpora 


nigra 


extends  to  the  anterior  margin  of  the  pupil,  and  in  the 
horse  it  is  quite  thick  in  the  upper  portion,  forming 
several  prominent  projections  into  the  pupillary  space. 
These  pigment  bodies  are  known  as  the  "corpora  nigra," 


24  OPHTHALMOLOGY  FOR  VETERINARIANS 

and  are  commonly  called  ' 'grape-kernels"  and  ' 'soot- 
balls."  The  pigment  of  the  posterior  layer  and  that 
in  the  meshes  of  the  stroma  give  color  to  the  iris,  and 
the  varied  colored  irides  depend  upon  the  amount  of 
pigment  deposited  in  them.  A  horse  with  little  or  no 
pigment  in  the  iris  is  called  "wall  eyed."  Albinos  are 
devoid  of  pigment.  The  white  rabbit  is  a  good  example. 
In  such  cases  a  pinkish  reflex  is  seen,  derived  from  the 
retinal  circulation. 

The  pupil  varies  in  size  and  shape  in  different  animals. 
In  fetal  life  a  delicate  membrane  covers  the  pupillary 
space,  known  as  the  membrana  pupillaris.  This  disap- 
pears a  few  days  or  weeks  before  birth,  though  in  some 
cases  portions  of  it  remain  in  threadhke  forms,  known  as 
a  persistent  pupillary  membrane,  which  is  often  mis- 
taken for  a  pathologic  condition. 

The  ciliary  body  is  closely  connected  to  the  sclerotic 
coat  from  the  ora  serrata  to  a  point  near  the  sclero- 
corneal  junction.  It  is  composed  of  muscular  fibers, 
connective  tissue,  blood-vessels,  and  pigment.  The  body 
is  circular  in  shape  in  relation  to  the  sclerocorneal 
margin.  By  making  a  vertical  or  horizontal  section  of 
the  globe  the  muscle  can  be  studied  longitudinally. 
Such  a  section  gives  it  a  triangular  appearance.  The 
muscle-fibers  are  of  two  kinds — the  longitudinal  and  the 
circular.  The  former  comprise  the  greater  portion,  and 
lie  externally  near  the  scleral  tissue,  and  are  called 
Briicke's  portion,  after  the  discoverer.    The  latter  form 


ANATOMY  OF  THE  EYE  25 

the  internal  base  of  the  muscle  body  and  were  discovered 
by  Heinrich  Muller;  hence,  it  is  called  Muller's  portion. 
At  the  anterior  zone  are  folds  of  connective-tissue 
stroma — seventy  or  more  in  number — intermixed  with 
numerous  blood-vessels  and  branched  pigment-cells. 
The  anterior  internal  portion  of  the  body  is  continuous 
with  the  iris. 

A  layer  of  pigmented  and  one  of  non-pigmented  cells 
lines  the  body,  and  these  are  continuous  with  the  poste- 
rior layers  of  the  iris  forward  and  the  chorioid  and 
retina  backward.  This  intimate  association  of  the 
pigment,  from  the  optic  disk  to  the  pupillary  border, 
has  given  it  the  name  of  the  uvea. 

The  ciliary  muscle  is  the  muscle  of  accommodation, 
and  by  its  contraction  the  lens  becomes  more  convex, 
shortening  its  focus,  and  accommodating  vision  for 
near  work.  This  and  the  sphincter  and  dilator  pupillae 
are  the  intrinsic  muscles  of  the  eyeball. 

The  lens  is  the  principal  refractive  medium.  It  is 
biconvex,  perfectly  transparent,  colorless,  circular  in 
shape,  and  is  enclosed  in  a  delicate  transparent  capsule. 
It  Kes  between  the  iris  and  the  vitreous,  where  it  rests 
in  a  fossa  in  the  latter  substance— the  fossa  petellaris. 
The  space  between  the  border  of  the  lens  and  the  ciliary 
muscle  is  known  as  circumlental  space.  The  anterior 
portion  supports  the  pupillary  border  of  the  iris. 

The  lens  is  composed  of  hexagonal  prisms,  arranged 
in  concentric  layers  supported  by  a  cement  substance. 


26  OPHTHALMOLOGY  FOR  VETERINARIANS 

The  center  or  nucleus  is  unstriated  and  becomes  scle- 
rosed as  age  advances.  It  is  supported  by  the  suspen- 
sory ligament  or  zonule  of  Zinn.  This  ligament  is  com- 
posed of  homogeneous  fibers,  which  arise  from  the 
ciHary  body  anterior  to  the  ora  serrata  and  the  ciliary 
processes,  and  it  is  fused  with  the  lens  capsule  near  the 
border.  The  space  between  the  fibers  as  they  diverge 
is  called  the  canal  of  Petit,  and  is  triangular  in  shape 
on  transverse  section.  The  capsule  is  similar  in  struc- 
ture to  the  suspensory  Hgament.  The  anterior  capsule 
has  a  layer  of  epithehal  cells  on  the  surface  next  the  lens, 
which  become  associated  with  the  lens  substance  near 
the  zonular  portion.  The  posterior  capsule  has  no 
epithelium. 

Like  the  cornea,  the  lens  has  no  blood-vessels  of  its 
own.  It  derives  its  nourishment  from  the  ciliary  proc- 
esses. 

The  vitreous  is  a  gelatinous  substance,  perfectly 
transparent  and  colorless.  It  fills  the  vitreous  chamber, 
or  that  portion  of  the  globe  posterior  to  the  lens,  and  it 
is  enclosed  in  a  delicate  structure  called  the  hyaloid 
membrane.  At  the  anterior  portion  is  a  depression  in 
which  rests  the  lens.    . 

The  vitreous  mass  is  composed  of  rounded  and 
branched  cells.  It  is  devoid  of  blood-vessels,  and  re- 
ceives its  nourishment  from  the  uvea.  In  the  center 
is  a  small  canal  which  serves  as  a  lymphatic  channel. 
This,  in  fetal  life,  was  traversed  by  the  hyaloid  artery 


ANATOMY  OF  THE  EYE  27 

from  the  optic  disk  to  the  posterior  lens  capsule.  In 
some  cases  portions  of  this  persist,  with  an  opacity  of 
the  central  portion  of  the  posterior  capsule,  known  as  a 
posterior  polar  cataract. 

Should  the  vitreous  become  fluid,  as  it  sometimes  does 
by  reason  of  disease,  the  tension  of  the  globe  is  much  de- 
creased and  the  retina  may  become  detached  by  loss  of 
support. 

The  conjunctiva  is  a  mucous  membrane,  and  covers 
the  anterior  half  of  the  globe,  except  that  portion  sup- 
plied by  the  cornea.  It  merges  with  the  anterior  epi- 
thelium of  the  cornea,  extending  over  the  sclera  as  far 
as  the  fornix,  where  it  folds  upon  itself  and  Hues  the 
posterior  surface  of  the  lid,  and  is  strongly  adherent  to 
the  tarsus.  This  portion  is  called  the  palpebral  conjunc- 
tiva. The  bulbar  portion  is  freely  movable  over  the 
sclera,  and  is  connected  to  it  by  the  loose  episcleral  tis- 
sue. At  the  inner  angle,  in  man,  is  a  fold  known  as  the 
plica  semilunaris,  which  is  said  to  be  a  rudimentary 
nictitans  membrane  so  prominent  in  animals.  Just 
inside  of  this  is  a  small  elevated  island  of  tissue  covered 
with  hairs,  known  as  the  caruncle. 

The  nictitans  membrane,  or  ''accessory  eyehd,"  is 
situated  near  the  nasal  angle,  between  the  globe  and  the 
side  of  the  orbit.  It  is  composed  of  elastic  fibrocartilage 
and  is  irregidar  in  form,  being  thick  and  somewhat 
prismatic  at  its  base  and  thin  anteriorly,  where  it  is  cov- 
ered with  a  fold  of  conjunctiva.    Posteriorly,  it  is  con- 


28  OPHTHALMOLOGY  FOR  VETERINARIANS 

tinuous  with  a  pad  of  fat  which  is  insinuated  between  all 
the  muscles  of  the  eye.  Its  internal  surface  is  concave 
and  its  external  surface  is  convex.  When  the  eye  is 
in  its  natural  position  only  the  margin  of  the  membrane, 
covered  by  conjunctiva,  is  perceptible,  the  rest  being 
buried  in  the  ocular  sheath;  but  when,  by  contraction 
of  the  straight  muscles,  the  globe  presses  upon  the  pad 
of  fat,  the  membrane  is  forced  out  and  covers  more  or 
less  of  the  cornea.  This  movement,  which  is  instan- 
taneous, is  for  the  purpose  of  removing  any  offending 
agent  from  the  surface  of  the  eye.  In  some  diseases,  as 
tetanus,  the  membrane  is  forced  outward  and  remains 
so.     It  is  vulgarly  called  the  ''haw  of  the  eye"  (Vaughn). 

The  nictitans  is  very  prominent  in  fowls  and  birds,  as 
well  as  in  quadrupeds  generally,  while  in  the  inhabitants 
of  the  sea  it  is  absent.  Its  function  is  associated  with  the 
"gland  of  Harder,"  which  is  a  sort  of  supplementary 
lacrimal  gland,  and  furnishes  an  abundance  of  unctuous 
fluid  in  conjunction  with  the  action  of  the  membrana 
nictitans.  It  is  described  as  a  ''reddish-yellow  gland," 
and  is  situated  beneath  the  membrana  nictitans,  at 
about  the  middle  of  its  outer  portion. 

As  these  organs  are  very  essential  for  the  protection  of 
the  cornea,  they  should  by  no  means  be  interfered  with 
surgically,  as  is  too  often  done  without  sufficient  reason. 


CHAPTER  II 

SYSTEMATIC  EXAMINATION  OF  THE  EYE 

The  symptoms  of  pathologic  conditions  in  animals' 
eyes  are  objective,  and,  in  order  to  be  able  to  distinguish 
them,  one  must  be  famihar  with  the  normal  conditions. 

Examine  normal  eyes  at  every  opportunity;  observe 
the  particular  size  and  shape  of  the  anterior  portion  in 
animals  of  different  kinds;  see  that  the  lids,  iris,  con- 
junctiva, etc.,  are  comparatively  uniform  in  size,  shape, 
color,  and  transparency.  If  one  lid  droops  more  than  the 
other  or  is  completely  closed,  it  indicates  a  partial  or 
complete  paralysis  of  the  muscle  that  elevates  the  Hd 
—the  levator  palpebrarum.  If  the  lid  fails  to  cover  the 
cornea  when  the  Hd  is  relaxed,  the  orbicularis  palpebrarum 
is  involved.  Should  the  lid  be  closed  and  raised  with 
much  resistance,  a  spasm  of  the  orbicularis  exists,  pro- 
duced by  the  presence  of  a  foreign  body  or  from  some 
other  reflex  cause.  Examine  the  border  of  the  lids  to  see 
that  the  lashes  are  properly  directed,  for  if  they  turn 
inward  they  act  the  same  as  a  foreign  body.  The 
puncta  lacrimalia  must  lie  in  close  apposition  to  the 
eyeball,  otherwise  they  fail  to  perform  their  function 
properly  and  epiphera  will  be  the  result.     Projections 

29 


30 


OPHTHALMOLOGY  FOR  VETERINARIANS 


in  various  portions  of  the  lid  indicate  the  presence  of 
tumors.  If  these  are  movable  and  free  from  the  skin, 
a  meibomian  duct  is  occluded,  resulting  in  the  forma- 
tion of  a  chalazion.  If  the  Hd  is  edematous,  look  for  a 
point  of  local  induration.  This  condition  may  accom- 
pany heart  and  kidney  lesions,  and  some  cases  of 
trichinosis. 

The  conjunctiva  should  be  transparent,  showing  the 
sclera  beneath  it.  If  it  is  congested,  note  carefully  the 
location.  An  injection  about  the  margin  of  the  cornea 
indicates  a  cyclitis;  a  localized  injection  over  the  site 
of  a  muscular  insertion  is  a  symptom  of  localized  tenon- 
itis; an  injection  of  the  peripheral  portion,  with  large 
radiating  vessels,  suggests  glaucoma. 

A  severe  chemosis  suggests  either  a  general  tenonitis 
or  some  affection  of  the  orbital  tissues.  It  sometimes 
occurs  with  a  purulent  conjunctivitis. 

The  cornea  under  normal  conditions  should  be  trans- 
parent. If  it  is  hazy,  determine  whether  this  is  super- 
ficial or  deep.  If  the  epithelium  is  intact,  and  the  reflex 
of  a  window-sash  on  the  corneal  surface  is  not  bent  or 
broken,  the  trouble  lies  posterior  to  BoAvman's  membrane. 
It  may  be  due  to  interstitial  disease  or  to  a  turbid  aque- 
ous and  deposits  on  the  posterior  corneal  layer. 

The  pupils  should  be  of  the  same  size,  though  rarely 
there  is  a  sHght  difference  normally.  A  large  pupil  in 
one  eye  indicates  paralysis  of  the  sphincter  muscle,  the 
use  of  a  mydriatic,  or  glaucoma.     A  small  pupil  indi- 


SYSTEMATIC  EXAMINATION  OF  THE  EYE  3 1 

cates  a  reflex  contraction  from  the  presence  of  a  foreign 
body  or  corneal  ulcer,  iritis,  or  the  use  of  a  myotic. 
Paralysis  of  the  sympathetic  causes  a  small  pupil  in 
both  eyes.  The  pupils  should  be  regular  in  shape. 
If  irregular,  iritis  is  usually  the  cause.  If  the  pupil  is 
not  clear,  look  for  a  cataract,  exudates  in  the  chambers, 
or  a  turbidity  of  the  vitreous. 

-  The  iris  should  be  clear  and  lustrous.  Both  irides 
should  be  alike  in  this  respect,  though  a  difference  in 
the  amount  of  pigment  exists  in  many  cases.  If  the 
iris  has  lost  its  brilliancy  and  has  changed  its  color 
somewhat,  an  iritis  may  exist.  A  tremulous  iris  is  the 
result  of  loss  of  support,  which  is  due  to  displacement 
of  the  lens,  absorption,  or  previous  extraction  of  the 
same.  The  iris  is  subject  to  cysts,  tubercular  growths, 
etc. 

The  normal  lens  is  diflicult  to  see  because  of  its  trans- 
parency; consequently,  the  pupil  should  be  perfectly 
clear  normally,  so  that  light  reflected  through  the 
pupil  from  the  ophthalmoscopic  mirror  will  show  a  red 
reflex,  otherwise  there  is  some  opacity  of  the  interven- 
ing media.  Any  opacity  of  the  lens  can  readily  be  seen 
by  obHque  illumination  or  by  the  aid  of  a  strong  lens 
with  the  ophthalmoscope.  A  lens  of  10  diopters  will 
disclose  floating  bodies  in  the  vitreous.  A  smaU  opacity 
posterior  to  the  lens  center  will  move  in  the  opposite 
direction  to  the  movement  of  the  eye.  A  complete 
cataract  can  be  seen  filling  the  whole  pupillary  space. 


32  OPHTHALMOLOGY  FOR  VETERINARIANS 

Always  try  the  tension  of  the  eye  with  the  bulbs  of 
the  index-fingers.  Place  both  fingers  over  the  upper 
lid,  above  the  cornea,  and  make  gentle  pressure.  A 
sense  of  normal  tension  can  only  be  acquired  by  prac- 
tice. An  increased  tension  indicates  glaucoma,  while 
a  decreased  tension  is  the  result  of  a  fluid  vitreous. 


CHAPTER  III 

DISEASES  OF  THE  LIDS 

From  without  inward  the  Hds  are  composed  of  skin,  a 
loose  areolar  tissue,  muscle,  the  tarsus,  and  conjunctiva. 

The  skin  is  freely  movable  because  of  the  loose  tissue 
beneath  it.  It  is  continuous  with  the  skin  of  the  fore- 
head, and  blends  with  the  conjunctiva  at  the  margin. 
At  this  point  is  a  growth  of  stiff  hairs — the  lashes — 
which  arise  from  the  margin  of  both  lids  usually,  though 
the  lower  lid  of  the  dog  and  pig  present  no  distinct  lower 
lashes. 

The  tarsus  is  the  framework,  and  affords  the  lid  firm- 
ness. The  upper  tarsus  is  larger  than  the  lower.  It  is 
not  cartilage,  but  it  is  composed  of  dense  fibrous  tissue. 
The  tarsi  are  connected  by  the  tarsal  ligaments  to  the 
lateral  walls  of  the  orbit  and  to  each  other  by  the  pal- 
pebral ligaments.  It  contains  the  meibomian  glands, 
which  are  about  forty  in  number.  These  glands  are 
arranged  in  parallel  rows,  and  they  have  their  exit 
through  small  ducts  which  open  at  the  margin  of  the 
lids,  posterior  to  the  roots  of  the  lashes.  The  muscle- 
fibers  are  those  of  the  orbicularis  and,  at  the  upper 
portion,  the  levator  palpebrarum.     The  fibers  of  these 

3  33 


34  OPHTHALMOLOGY  FOR  VETERINARIANS 

muscles   run   horizontally   and   vertically   and   are   in- 
timately associated. 

The  conjunctiva  is  the  mucous  membrane  lining  the 
lids.  It  is  strongly  adherent  to  the  tarsus.  Superior 
to  the  tarsus,  it  folds  upon  itself,  forming  a  sort  of  culde- 
sac,  known  as  the  fornix  conjunctivae.  This  portion  of 
the  conjunctiva  contains  numerous  glands,  resembling 
the  lacrimal  gland  in  structure.  The  mucous  glands 
afford  a  secretion  to  lubricate  the  lids  in  the  act  of 
winking  and  to  moisten  the  cornea. 

The  lids  contain  a  portion  of  the  lacrimal  apparatus. 
The  outlet  ducts  from  the  lacrimal  gland  open  at  the 
posterior  portion  of  the  superior  and  external  part  of  the 
upper  lid.  The  drainage  canals  have  their  origin  at 
points  known  as  the  puncta  lacrimalia.  These  are 
situated  near  the  inner  angle  of  the  Hds,  nearly  opposite 
each  other.  Small  canals  run  from  these  points,  and 
these  unite  at  the  lacrimal  sac,  internal  to  the  inner 
canthus.  This  sac  leads  into  the  nasal  duct— a  bony 
canal— which  terminates  in  the  nasal  cavity  opposite 
the  middle  turbinate. 

The  anatomic  arrangement  of  these  structures  is 
somewhat  different  in  quadrupeds  and  fowls.  The 
puncta,  instead  of  pin-point  openings  near  the  border 
of  the  lids,  are  large  oval  openings  in  the  conjunctiva 
of  the  Hds  near  the  inner  portion.  The  canals  are  also 
much  larger  in  proportion. 

The  outer  surface  of  the  lids  is  subject  to  the  same 


DISEASES  OF  THE  LIDS  35 

diseases  as  other  surfaces  of  the  skin,  and  often,  when 
skin  diseases  occur  about  the  head  and  face,  the  eyehds 
become  involved. 

Edema  is  often  a  symptom  of  some  remote  disease, 
such  as  the  heart  or  kidneys.  It  may  also  be  caused  by 
local  infection,  infiltration,  and  suppuration-the  result 
of  a  blow,  fracture  of  the  bony  orbit,  or  rupture  of  the 
-orbital  vessels,  erysipelas,  and  other  skin  affections. 
Trichinosis  is  also  a  cause.  It  is  doughy  to  the  touch 
and  may  pit  on  pressure. 

Emphysema  is  due  to  the  escape  of  air  into  the  cellu- 
lar tissue  from  fracture  of  the  wall  of  one  of  the  ad- 
jacent sinuses,  and  may  accompany  emphysema  of  the 
neighboring  structures.  In  this  condition  a  crackhng 
sensation  is  noticeable  to  the  touch.  It  will  subside 
as  soon  as  the  cause  has  been  removed. 

Ecchymosis,  or  ''black  eye,"  is  due  to  rupture  of 
the  subcutaneous  vessels  and  the  effusion  of  blood  be- 
neath the  skin.  It  is  usually  due  to  direct  violence  or 
to  rupture  of  remote  vessels.  Ice-cold  applications, 
evaporating  lotions,  or  the  lead-and-opium  wash  may  be 
used  with  benefit. 

Burns  are  caused  by  too  hot  appHcations,  powder 
explosions,  fires,  caustics,  etc.  They  are  divided  by 
degree,  the  same  as  burns  on  other  portions  of  the  body. 
The  treatment  depends  upon  the  degree.  Those  of 
mild  degree  may  be  treated  with  dusting-powders  of 
boric  acid,  etc.,  while  the  deeper  burns  should  be  treated 


36  OPHTHALMOLOGY  FOR  VETERINARIANS 

with  soothing  and  antiseptic  oils.  Powder  grains  may 
be  removed  by  the  appHcation  of  hydrogen  peroxid 
3  parts  to  glycerin  i  part.  Ordinarily  burns  may 
be  treated  upon  general  principles.  In  severe  cases 
ectropion  may  follow  by  reason  of  large  cicatrices,  and 
repair  will  have  to  be  accomplished  by  plastic  opera- 
tions. 

Wounds  may  be  of  the  incised,  lacerated,  or  contused 
type,  and  should  be  treated  by  general  surgical  measures. 
The  surgery  of  the  eyehd,  however,  is  very  difhcult, 
when  we  consider  the  necessity  of  adapting  well  each 
of  its  important  structures. 

Ectropion,  or  eversion  of  the  Hd,  is  caused  by  burns, 
injuries,  etc.,  which  cause  a  cicatrix  of  the  skin  surface. 
When  a  severe  ectropion  exists  the  eye  is  very  unsightly. 
The  conjunctiva  is  constantly  exposed  and  reddened. 
It  becomes  greatly  irritated  and  inflamed  by  exposure 
and  want  of  protection.  Ectropion  may  also  be  the 
result  of  paralysis.  The  lower  Kd  is  more  often  involved, 
in  which  case  the  punctum  is  turned  outward,  and  the 
tears,  instead  of  flowing  in  their  natural  channel,  flow 
over  the  cheek  (epiphora)  and  cause  much  irritation. 
The  treatment  is  principally  surgical. 

Entropion,  or  inversion  of  the  lid,  is  caused  by  de- 
structive diseases  of  the  conjunctiva  and  tarsus.  It  is 
usually  accompanied  with  trichiasis.  Intense  irritation 
of  the  cornea  is  the  result  of  this  condition,  and  often 
keratitis  with  opacities  follow.    The  treatment  is  surgical. 


DISEASES  OF  THE  LIDS  37 

Lagophthalmus,  or  inability  to  close  the  lid,  is  the 
result  of  paralysis  of  the  orbicularis  palpebrarum,  through 
pressure  upon  or  disease  of  the  seventh  nerve.  Usually 
facial  paralysis  accompanies  this  condition  when  the 
affection  of  the  nerve  is  posterior  to  the  branches  sup- 
plying the  orbicularis.  Destruction  of  the  cornea  may 
ensue  by  exposure.  Temporary  relief  may  be  had  by 
drawing  the  lids  together,  and  keeping  them  closed  by 
the  use  of  adhesive  plaster.  The  cause  of  the  paralysis 
should  be  looked  for  and  removed. 

Ptosis,  or  drooping  of  the  lid,  may  be  partial  or  com- 
plete, and  is  due  to  paralysis  of  the  levator  palpebrarum 
by  reason  of  pressure  upon  or  disease  of  the  third  nerve, 
or  that  portion  of  it  supplying  this  muscle.  It  may  be 
congenital  from  absence  of  the  muscle.  Injury  may  also 
be  the  cause.  In  all  cases  of  paralysis  the  treatment  must 
be  based  upon  general  principles. 

Tarsitis,  or  inflammation  of  the  tarsus,  is  the  result 
of  old  trachoma,  syphihs,  tuberculosis,  etc.  It  is  a 
chronic  thickening  of  the  tissue,  with  infiltration  of  the 
tarsal  elements.  It  may  follow  chronic  infection  of  the 
meibomian  glands.  The  lid  is  thick  and  heavy  over 
the  site  of  the  tarsus,  and  oftentimes  partial  ptosis  and 
blepharitis  are  present.  The  treatment  depends  upon 
the  cause.  Resolvent  ointments  have  been  recommended 
combined  with  massage.  In  extreme  and  chronic  cases 
the  tarsus  has  been  removed. 

Elephantiasis  is  due  to  hypertrophy  of  the  skin  and 


38  OPHTHALMOLOGY  FOR  VETERINARIANS 

subcutaneous  tissue.  It  may  be  confined  to  one  lid  only 
or  both  lids  may  be  affected.  It  is  often  the  result  of 
continued  attacks  of  inflammation  of  these  tissues. 

Blepharospasm  is  an  involuntary  contraction  of  the 
lid.  It  may  be  clonic  or  tonic  in  character.  It  is  usually 
reflex,  and  is  due  to  some  irritation  of  the  seventh  nerve. 
The  lid  is  spasmodically  contracted  when  a  foreign  body 
is  present  and  also  in  some  diseases  of  the  cornea.  The 
mild  clonic  type  is  often  due  to  nervous  diseases,  chorea, 
habit,  etc.  In  these  cases  nerve  tonics  and  rest  are  of 
benefit.  In  the  animal,  more  likely  a  foreign  body  is  the 
cause.    Remove  the  cause. 

Ankyloblepharon  is  a  condition  in  which  the  edges 
of  the  lids  have  grown  together.  It  is  usually  caused 
from  traumatism  or  disease,  or  may  be  due  to  a  con- 
genital defect,  when  the  Hds  fail  to  open,  as  is  often 
seen  in  kittens  and  other  pets.  An  operation  is  the 
only  relief,  though  in  congenital  cases  the  lids  will 
usually  separate  if  one  will  give  nature  sufficient  time 
to  do  its  work. 

Blepharitis  marginalis,  an  inflammation  of  the  lid, 
is  known  as  blepharitis,  but  the  former  term  designates 
a  local  inflammation  along  the  margin.  There  are  two 
principal  types — the  superficial  and  the  ulcerative.  The 
superficial  type  is  manifest  by  the  presence  of  redness 
and  swelling,  together  with  the  formation  of  crusts, 
which  usually  occur  about  the  lashes,  and  frequently 
cause  them  to  fall  out  by  slight  friction.     The  hair- 


DISEASES  OF  THE  LIDS  39 

follicles  are  not  involved,  and  the  lashes  grow  again  by 
proper  treatment.  It  often  occurs  in  strumous  sub- 
jects, and  accompanies  catarrhal  and  other  types  of 
conjunctivitis  and  the  presence  of  pediculi. 

In  the  ulcerative  type  the  above  symptoms  are 
present,  but  more  severe,  together  with  ulceration, 
which  occurs  beneath  the  crusts.  This  ulceration  in- 
-vades  the  hair-folKcles,  and  when  the  lashes  are  once 
lost  they  fail  to  grow  again.  It  is  often  due  to  infection. 
Severe  itching  is  often  present,  and  rubbing  the  hds 
tends  to  create  a  fresh  focus  for  the  growth  of  the 
organisms.  The  lids  are  heavy  and  partly  closed,  and 
the  matting  together  of  the  lashes  with  crusts  and 
secretion  makes  the  animal  look  as  though  it  were  suffer- 
ing with  some  severe  •  constitutional  disease. 

Treatment. — This  should  be  directed  to  the  cause. 
If  conjunctivitis  or  other  diseases  of  adjacent  struc- 
tures exist,  they  should  be  met  by  appropriate  thera- 
peutic measures. 

In  mild  cases  soften  the  crusts  with  vaselin,  and, 
after  this  has  remained  on  for  several  hours,  wash  it  off 
with  a  mild  alkaline  solution,  remove  the  crusts  that 
may  remain,  and  apply  an  ointment  composed  of  yellow 
oxid  of  mercury  6  grains,  and  vaselin  i  ounce. 

In  the  ulcerative  type  the  above  treatment  may  be 
employed,  and  when  the  lids  are  free  from  crusts  the 
ulcers  may  be  touched  with  a  2  to  10  per  cent,  silver 
nitrate  solution,  the  tincture  of  iodin,  or  a  25  per  cent. 


40  OPHTHALMOLOGY  FOR  VETERINARIANS 

solution  of  carbolic  acid  in  alcohol.  This  treatment 
should  be  repeated  as  occasion  requires,  and  care  should 
be  exercised  that  none  of  the  solutions  get  into  the  eye. 
The  general  health  of  the  animal  should  always  be 
considered. 

Hordeolum,  or  stye,  is  a  localized  infection  about 
a  hair-foHicle,  resulting  in  suppuration.  A  stye  may 
occur  independent  of  blepharitis,  though  they  often 
occur  together.  Pain,  localized  tenderness,  and  swell- 
ing are  the  prominent  symptoms.  In  some  cases  a  pro- 
found edema  of  the  whole  lid  occurs.  Styes  often  ap- 
pear in  succession,  or  two  or  more  may  occur  at  the 
same  time.  In  the  late  stage  of  suppuration  they  tend 
to  point  and  rupture  of  their  own  accord. 

Treatment. — Much  the  same  treatment  as  in  blephari- 
tis may  be  employed.  When  the  stye  points  it  is  better 
to  open  it  with  a  small  sharp-pointed  instrument  and 
express  the  contents.  Protect  the  opening  with  a  little 
flexible  collodion. 

Chalazion. — This  is  a  disease  of  the  meibomian  glands, 
situated  in  the  tarsus,  and  the  result  of  stoppage  of  the 
outlet  ducts  which  open  at  the  inner  edge  of  the  Kd,  just 
posterior  to  the  roots  of  the  lashes.  It  is  manifest  by  a 
localized  tumor  in  the  lid,  movable  and  free  from  the 
skin.  As  the  meibomian  gland  is  essentially  a  sebaceous 
gland,  a  chalazion  is  like  a  sebaceous  cyst  in  character 
and  is  filled  with  sebaceous  matter.  It  often  goes  on 
to  suppuration,  and  may  discharge  its  contents  either 


DISEASES  OF  THE  LIDS  41 

through  the  skin  or  conjunctival  surface.  It  may, 
however,  become  absorbed  before  reaching  the  stage  of 
suppuration  and  disappear  spontaneously,  or  it  may 
remain  permanently  enlarged  and  undergo  fibroid 
change.  Large  tumors  press  upon  the  eyeball  and 
produce  much  discomfort,  besides,  they  are  very  un- 
sightly. 

Treatment.— In  the  early  stages  the  tumor  can  some- 
times be  aborted  by  gradually  milking,  or  pressing  out 
the  contents  of  the  duct,  and  allowing  free  drainage. 
If  suppuration  has  taken  place,  the  lid  may  be  everted 
and  the  tumor  incised  at  the  place  of  pointing,  and  the 
contents  scraped  out  with  a  small  curet.  If  the  tumor 
remains  chronically  enlarged,  as  it  often  does,  it  is 
better  to  dissect  it  out  from  the  skin  surface.  By  this 
method  the  sac  and  all  may  be  removed,  and  there  is 
less  liability  of  the  tumor  recurring.  They  may  appear 
in  other  portions  of  the  lid  or  several  tumors  may  co- 
exist. When  excised  from  the  outside  the  parts  may  be 
brought  together  with  a  single  stitch  and  the  whole 
covered  with  collodion. 

Tumors  of  the  Eyelid.— The  lid  is  subject  to  benign 
and  mahgnant  growths.  The  former  are  the  angioma, 
a  vascular  tumor,  and  usually  congenital;  the  granuloma, 
an  excess  growth  of  healthy  tissue,  is  nature's  attempt  to 
heal  a  wound,  which  may  appear  as  a  flat  growth,  cover- 
ing a  large  surface,  or  a  polypoid  soft  growth  at  the  mouth 
of  a  sinus,  a  papilloma  or  wart  on  the  surface  or  border 


42  OPHTHALMOLOGY  FOF   VETERINARIANS 

of  the  lid,  and  certain  growths  of  a  horny  nature  about 
these  localities. 

The  malignant  tumors  are  the  sarcoma  and  the  car- 
cinoma. The  former  occurs  in  the  young,  though  often 
seen  in  older  subjects,  either  as  a  primary  tumor  or 
extending  from  sarcoma  of  the  orbit. 

Carcinoma  occurs  as  an  epithelial  cancer,  charac- 
terized by  a  slow  ulceration,  hke  epithehoma  in  other 
portions.  A  diagnosis  can  properly  be  made  only  by  the 
use  of  the  microscope.  The  proper  treatment  in  the 
case  of  all  tumors  is  excision  of  the  same.  The  malig- 
nant types,  especially  the  epithelioma,  have  been  treated 
by  the  a:-ray  w^ith  excellent  results. 

Ulcers  of  the  Lid. — Ulcers  of  the  skin  surface  of  the 
lid  are  not  infrequent  as  the  result  of  burns  and  other 
injuries  and  local  and  constitutional  diseases.  Lupus 
is  particularly  Hable  to  affect  the  lid  when  the  skin  in 
the  immediate  region  is  diseased.  Cowpox  and  other 
skin  affections  which  may  attack  the  lid  may  be  followed 
by  ulceration. 

The  cause  must  be  treated  as  well  as  the  ulcers  them- 
selves. Cleanliness  is  one  of  the  main  things  to  observe, 
together  with  protection  and  stimulation  to  healthy 
granulation,  as  in  the  treatment  of  ulcers  of  other  por- 
tions of  the  body. 

Abscess  of  the  Lid. — ^This  is  often  phlegmonous  in 
character,  and  is  caused  by  direct  injury,  diseases  of  the 
bones  in  the  neighboring  region,  erysipelas,  or  anthrax. 


DISEASES  OF  THE  LIDS  43 

The  general  symptoms  of  purulent  inflammation 
accompany  it — edema,  induration,  swelling,  pain,  and 
tenderness  on  pressure.  The  swelhng  is  so  intense  as  to 
completely  close  the  hd.  The  pus  is  diffused  through  the 
tissues,  and  gangrenous  destruction  of  the  tissues  may 
result.  This  is  followed,  in  the  process  of  healing,  by 
cicatrices,  which  interfere  with  the  closure  of  the  lid  or 
produce  ectropion.    Both  lids  are  often  affected. 

Treatment, — As  soon  as  one  can  determine  the  pres- 
ence of  pus,  a  free  opening  should  be  made  and  drainage 
estabHshed,  hot  bichlorid  compresses  appHed,  and  every 
effort  made  to  get  the  best  results  and  prevent  as  httle 
deformity  as  possible  in  the  process  of  heaHng.  Co- 
existing conditions  should  always  be  sought  for  and 
promptly  treated. 

Trichiasis.— This  is  an  abnormal  position  of  the 
eyelashes.  They  grow  inward  or  backward  toward  the 
globe,  instead  of  outward.  It  is  often  caused  by  con- 
traction of  the  inner  surface  of  the  eyehd  from  diseases 
of  the  conjunctiva  and  tarsus.  It  produces  great  irrita- 
tion of  the  cornea  by  constantly  scratching  it  in  the  act 
of  winking.  If  this  irritation  continues,  inflammation 
and  opacity  of  the  cornea  may  follow. 

Treatment.— 1(  only  a  few  lashes  turn  inward  they  may 
be  extracted  with  a  pair  of  forceps.  This  operation 
must  be  repeated  at  regular"  intervals,  for  the  short 
stubby  lashes  that  grow  again  cause  more  irritation 
than  the  long  silky  ones.      The  hair-folHcles  may  be 


44  OPHTHALMOLOGY  FOR  VETERINARIANS 

destroyed  by  electrolysis.  If  the  condition  is  general 
and  accompanied  with  entropion,  as  it  often  is,  one  of 
several  operations  may  be  performed. 

Distichiasis. — This  is  a  double  row  of  lashes  on  the 
same  lid.  The  posterior  row  may  be  removed  by  special 
operation. 


CHAPTER  IV 

OPERATIONS  ON  THE  LIDS 

Operations  on  the  lids  are  necessary  to  correct 
certain  deformities,  such  as  ectropion,  entropion,  trich- 
iasis, and  ptosis.  In  doing  operations  on  the  Hds 
requiring  incisions  of  the  external  parts  In  animals  the 
hair  should  be  shaved  from  the  part  incised,  so  that  it 
will  not  be  caught  in  the  wound  when  the  sutures  are 
applied. 

The  same  antiseptic  and  aseptic  precautions  should 
be  used  as  in  doing  operations  on  other  portions  of  the 


Fig.  9. — Knapp's  lid  clamp.       (de  Schweinitz,  "Diseases  of  the  Eye.") 

body,  but  the  operator  should  be  careful  that  strong 
antiseptic  solutions  do  not  enter  the  inner  portion  of  the 
lids  and  injure  the  cornea.  The  lid  clamp  or  horn 
spatula  (Fig.  9)  should  be  placed  beneath  the  hd  to 
afford  more  resistance  and  firmness  when  making  in- 
cisions and  to  protect  the  eyeball.    This  should  be  sup- 

45 


46 


OPHTHALMOLOGY  FOR  VETERINARIANS 


ported  and  gently  raised  by  an  assistant  during  the 
operation. 

The  illustrations  of  these  operations  are  shown  on  the 
human  eye,  and  are  taken  from  Dr.  de  Schweinitz's 
work  on  ' 'Diseases  of  the  Eye,"  published  by  W.  B. 
Saunders  Co. 

Ectropion. — There  are  numerous  operations  for  the 
correction  of  ectropion.  One  of  the  simplest  is  the 
Wharton  Jones'  operation  (Figs.  lo  and  ii). 


Fig.  lo.  Fig.  II. 

Figs.  lo,  II. — Wharton  Jones'  operation  for  ectropion,     (de  Schweinitz, 

"Diseases  of  the  Eye.") 


A  V-shaped  incision  of  the  skin  is  made,  the  apex  ex- 
tending downward.  The  skin  is  undermined,  and  the 
central  portion  elevated,  when  the  whole  is  brought  to- 
gether as  shown  in  Fig.  ii.  This  allows  a  more  lax 
condition  of  the  skin  of  the  lid,  and  is  a  good  operation 
in  ectropion  following  small  cicatrices. 

Success  has  been  attained  in  numerous  cases  by  the 
writer  by  doing  the  Kuhnt-Szymanowski  operation,  which 


OPERATIONS  ON  THE  LIDS  47 

is  described  as  follows  by  Meller  in  his  work  on  ''Oph- 
thalmic Surgery."  He  divides  the  operation  into  four 
steps:  The  first  step  consists  in  ''sphtting  the  lower 
lid  in  the  intermarginal  border."  He  uses  a  lancet  or 
keratome  for  this  purpose,  passing  it  in  between  the 
skin  and  the  tarsus,  using  the  thumb  and  index-finger 
as  a  guide,  so  that  the  tarsus  or  skin  will  not  be  wounded. 
•He  starts  ''sUghtly  to  the  inner  side  of  the  middle  of  the 
lid  and  goes  exactly  to  the  external  canthus." 


v>^  --^. 


A.. 


'%f^::,^:^^,^^' 


Fig.  12. — Showing  the  formation  of  the  triangle  of  skin,  which  is  later 
removed,     (de  Schweinitz,  "  Diseases  of  the  Eye.") 

As  the  Hd  is  very  vascular,  hemorrhage  must  be  stopped 
with  adrenalin  or  compression. 

'The  second  step  is  the  excision  of  a  triangular  piece 
from  the  tarsus."  The  size  of  this  piece  depends  upon 
the  degree  of  the  deformity.  This  piece  is  best  excised 
with  a  strong  pair  of  straight  scissors.  The  overlying 
conjunctiva  is,  of  course,  included  in  the  excision. 

"The  third  step  consists  in  the  excision  of  a  triangular 


48 


OPHTHALMOLOGY  FOR  VETERINARIANS 


piece  of  skin  from  the  region  of  the  external  can  thus." 
This  excision  is  first  mapped  out,  and  the  skin  divided 
with  a  sharp  scalpel. 

"The  fourth  step  consists  in  uniting  the  open  wounds." 
First  unite  the  wound  in  the  tarsus,  then  apply  the 
sutures  in  the  skin  of  the  lid,  as  shown  in  Fig.  13. 


Fig.  13. — Showing  the  condition  after  the  excision  of  the  triangular 
piece  of  skin  and  the  undermining  of  the  lid,  which  is  turned  outward. 
The  sutures  are  in  place,     (de  Schweinitz,  "  Diseases  of  the  Eye.") 


The  object  is  to  unite  the  parts  neatly,  and  to  produce 
traction  on  the  lower  Kd  to  hold  the  tarsus,  which  was 
everted,  in  its  normal  position. 

The  sutures  may  be  removed  in  from  five  to  seven 
days,  but  it  is  well  to  let  them  remain  long  enough  for 
good  union  to  take  place.  If  the  operation  is  done  under 
aseptic  precautions,  the  wounds  will  heal  by  first  in- 
tention. 

At  a  meeting  of  the  American  Medical  Association, 


OPERATIONS  ON  THE  LIDS  49 

in  1909,  Dr.  S.  Lewis  Ziegler  described  a  method  of  "gal- 
vanocautery  puncture  in  ectropion  and  entropion."  He 
uses  a  special  clamp  for  this  purpose,  in  which  the  lid 
is  fixed;  then  makes,  in  ectropion,  about  six  punctures 
of  the  tarsus  at  equal  distances  apart  with  a  special 
galvanocautery  tip.  For  entropion,  the  punctures  are 
made  on  the  skin  surface.  He  has  seldom  seen  any 
-reaction  following  its  use.  If  after  the  first  operation 
the  result  is  not  satisfactory,  the  operation  may  be  re- 
peated in  two  or  three  weeks. 

In  extensive  cicatrices,  or  in  cases  of  destruction  of  the 
tissues  of  the  lid,  plastic  operations  are  often  done  to 
restore  the  lid.     Such  operations  are  well  illustrated  in 

Figs.  14-17- 

The  cicatrix  or  ulcerated  surface  is  excised  and  new 
tissue  suppHed  by  a  flap  from  the  cheek  or  forehead. 
If  too  much  tension  is  produced  in  drawing  together  by 
sutures  the  wound  from  which  the  flap  was  taken,  it  may 
be  covered  with  Thiersch  grafts.  Such  grafts  are  taken 
from  the  leg  usually.  The  hair  must  first  be  shaved  and 
the  site  made  as  aseptic  as  possible.  A  portion  of  the 
upper  surface  of  the  skin  is  then  cut  away  with  a  to-and- 
fro  motion  of  the  razor.  The  razor  should  be  flooded 
with  normal  salt  solution,  so  that  the  grafts  will  slide 
off  easily  without  curling.  They  should  be  imme- 
diately transferred  as  soon  as  ah  bleeding  has  been 
stopped.      The   grafts   are   then   protected   with    per- 


50  OPHTHALMOLOGY  FOR  VETERINARL\NS 


Fig.  14. 


Fig.  IS- 
Figs.  14,  15. — Restoration  of  the  lower  lid  by  Dieffenbach's  method. 
The  diseased  tissue  has  been  removed  in  a  triangular  flap,  a-b-c.  This 
defect  is  covered  by  a  flap  taken  from  the  cheek,  indicated  by  the  dotted 
lines,  b-d,  d-e,  with  the  result  shown  in  Fig.  15.  The  remaining  gap 
may  be  covered  with  Thiersch  grafts,  (de  Schweinitz,  "  Diseases  of  the 
Eye.") 

for  a  ted  rubber  tissue,  over  which  is  placed  a  compress 
of  sterile  gauze  wet  with  normal  salt  solution. 


OPERATIONS  ON  THE  LIDS 


SI 


Fig.  i6. 


i'ig.  17- 
Figs  i6  17.— Restoration  of  lower  lid  by  Burow's  method.  The  dis- 
eased tissue  is  removed  with  the  flap  a-h-c.  The  horizontal  incision  is 
prolonged  upon  the  temple  and  forms  the  basis  of  the  triangle  a-d-e. 
This  flap  (B)  being  removed,  the  cutaneous  flap  a-c-d  is  dissected  up  and 
drawn  inward  so  that  the  angle  a  is  sutured  at  the  point  b,  and  a-J  forms 
the  free  border  of  the  lid.  c-a  is  now  united  with  c-b,  and  d-e  with  a  e 
with  the  result  shown  in  Fig.  17.    (de  Schweinitz,  "Diseases  of  the  Eye.  ) 

Entropion.— This   is   mostly   confined   to   the  upper 
lid.     To  correct  this  it  is  necessary  to  cause  traction 


52 


OPHTHALMOLOGY  FOR  VETERINARIANS 


of  the  skin  upward.    The  Hotz-Anagnostakis  operation 
meets  the  indications  (Fig.  i8). 

"A  transitive  incision  from  canthus  to  canthus  is 
made  through  the  skin  and  subjacent  tissue."  The  in- 
cision should  be  slightly  curved,  and  should  follow  the 
upper  border  of  the  tarsus,  6  to  8  mm.  above  the  border 


Fig.  1 8. — Operation  of  Anagnostakis  and  Hotz.       (de  Schweinitz,     Dis- 
eases of  the  Eye.")  - 

at  the  center  and  2  mm.  above  the  canthi.  The  wound 
is  then  separated,  and  a  narrow  bundle  of  the  muscle- 
fibers,  which  run  transversely  with  the  upper  border 
of  the  tarsus,  is  exsected  with  the  scissors  and  for- 
ceps. Three  sutures  are  applied,  one  in  the  middle  and 
one  at  each  side,  at  about  equal  distances  apart.  The 
center  needle  is  first  introduced  through  the  skin  only 


OPERATIONS  ON  THE  LIDS  53 

of  the  lower  portion  of  the  wound,  then  thrust  through 
the  upper  border  of  the  tarsus  and  the  tarso-orbital 
fascia,  as  well  as  the  skin  at  the  upper  portion.  The 
lateral  needles  are  placed  in  the  same  manner.  A  good 
needle-holder  should  be  used  in  this  operation,  as  well 
as  in  all  operations  on  the  lids  (Fig.  18). 

Trichiasis. — The  above  operation  is  a  very  satisfac- 
tory one  for  the  correction  of  this  condition. 

When  only  a  few  lashes  turn  inward  they  may  be 
extracted  with  a  pair  of  ciHum  forceps  (Fig.  19).  The 
lashes  may  grow   again,   and  the   short  stubby  hairs 


at 

Fig.  19. — Cilium  forceps,     (de  Schweinitz,  "  Diseases  of  the  Eye.") 

cause  much  irritation  of  the  cornea  if  they  happen  to 
be  central. 

Electrolysis  is  used  with  success  in  some  cases  to 
destroy  the  hair-follicles.  One  can  make  an  apparatus 
with  three  dry  cells,  two  pieces  of  wire,  a  needle,  and  a 
sponge.  Connect  the  batteries,  and  connect  the  wire 
with  the  needle  on  one  end,  to  the  negative  pole;  to  the 
positive  pole  attach  the  wire  with  the  sponge  on  it,  and 
the  apparatus  is  ready  for  use.  Pass  the  needle,  parallel 
with  the  hair,  to  its  root.  Wet  the  sponge  and  place  it 
on  the  cheek  or  forehead,  after  denuding  the  spot 
of  hair.  As  soon  as  the  contact  is  made  a  whitish  foam 
will  appear  about  the  entrance  of  the  needle.    The  sponge 


54  OPHTHALMOLOGY  FOR  VETERINARIANS 

can  now  be  removed  and  the  needle  withdrawn,  when 
the  lash  will  be  easily  extracted,  root  and  all. 

When  trichiasis  is  complete,  ablation  of  the  hair- 
follicles  according  to  Flarer's  method  is  the  best  to 
perform.  The  hd  is  split  posterior  to  the  roots  of  the 
lashes,  and  just  anterior  to  the  openings  of  the  meibo- 
mian ducts,  the  full  length  of  the  lid,  transversely,  then 
again  split  anterior  to  the  lashes,  the  scalpel  meeting 
the  bottom  of  the  first  incision,  just  beyond  the  roots. 
The  portion  containing  the  cilia,  complete,  must  then 
be  detached,  and  the  wound  allowed  to  heal  by  granu- 
lation. 

When  the  palpebral  fissure  is  contracted  by  reason 
of  chronic  diseases  of  the  conjunctiva,  which  often 
causes  entropion  and  trichiasis,  an  operation  known  as 
canthotomy  may  be  performed.  A  pair  of  straight, 
blunt-pointed  scissors  is  placed  horizontally,  one  point 
beneath  the  outer  canthus  and  the  other  above,  when 
the  tissues  between  the  blades  are  divided  with  one 
snip.  This  reheves  the  pressure  of  the  Hd  on  the  cor- 
nea and  relaxes  the  tension  of  the  border  of  the  lid. 

Canthoplasty  is  the  term  used  for  this  operation 
when  sutures  are  appHed.  These  sutures  are  usually 
used,  one  at  the  extreme  angle  of  the  wound  and  one 
above  and  one  below,  bringing  the  conjunctiva  and 
skin  together  (Fig.  20). 

Tarsorrhaphy  is  performed  when  it  is  desired  to  de- 
crease the  length  of  the  palpebral  fissure.     A  small 


OPERATIONS  ON  THE  LIDS  55 

flap,  including  the  hair-follicles,  is  removed  from  the 
upper  and  lower  Kds,  at  the  outer  angle,  the  length 
of  the  flaps  to  be  determined  by  the  amount  of  cor- 
rection desired,  and  the  denuded  surfaces  are  then 
united  by  sutures. 

Ankyloblepharon.— A  complete  division  of  the  hd 
may  be  made  at  the  natural  line  of  separation.  Begin 
at  the  outer  canthus,  pick  up  the  Hd  with  the  fixation 


Fig.  20. — Canthoplasty.     (Meyer.) 

forceps,  and  make  a  small  horizontal  slit  through  the 
hd,  being  careful  not  to  w^ound  the  globe.  Pass  a  small 
grooved  director  through  this  opening,  and  with  it  gently 
raise  the  lid  from  the  eye.  Pass  in  a  pair  of  small  sharp, 
probe-pointed  scissors  to  the  heel,  and,  directed  by 
the  probe,  divide  the  lid  with  one  cut,  if  possible,  to 
the  inner  canthus.  Fine  silk  sutures  should  be  used  to 
unite  the  conjunctiva  to  the  skin,  using  care  that  the 
knots  remain  externally. 


56  OPHTHALMOLOGY  FOR  VETERINARIANS 

Union  readily  takes  place,  and  the  sutures  may  be 
removed  in  about  four  days. 

One  should  not  be  too  ready  to  do  this  operation, 
as  nature  may  perform  her  work,  if  given  sufficient 
time,  in  the  case  of  all  pet  animals. 

Ptosis. — Panas'  operation  for  ptosis  is  probably  one 
of  the  most  popular.  Posey  gives  an  excellent  descrip- 
tion of  the  operation  as  follows:  ''Two  horizontal 
incisions  are  made,  the  lower  at  the  orbital  margin, 
and  along  the  top  of  the  flap  with  a  sHght  convexity 
upw^ard,  and  not  quite  an  inch  long;  the  higher  one  a 
Httle  longer,  and  at  the  upper  border  of  the  eyebrow. 
A  flap  of  the  skin  and  muscle  is  now  dissected  from  the 
tarsus  down  to  the  cihary  border,  but  the  septum 
orbitce  (suspensory  ligament)  of  the  lid  is  not  disturbed. 
The  bridge  of  tissue  between  the  two  horizontal  in- 
cisions is  undermined  without  cutting  the  periosteum  or 
septum  orbitae.  The  flap  is  then  drawn  up  under  the 
bridge  by  means  of  sutures  and  fastened  to  the  upper 
edge  of  the  higher  incision.  When  the  flap  is  so  fixed, 
the  traction  tends  to  cause  ectropion,  and  a  suture  is, 
therefore,  placed  at  each  side,  passing  deeply  through 
the  septum  orbitae  and  conjunctiva,  but  not  the  skin, 
and  it  also  is  inserted  in  the  upper  lip  of  the  higher 
incision,  so  as  to  correct  the  tendency  to  eversion." 


CHAPTER  V 

DISEASES  OF  THE  LACRIMAL  APPARATUS 

The  principal  diseases  of  the  lacrimal  apparatus  in 
the  animal  are  those  which  affect  the  lacrimal  sac 
and  nasal  duct. 

Dacryocystitis.— This  is  an  inflammation  of  the 
lacrimal  sac.  It  may  be  catarrhal  or  purulent.  In 
the  purely  catarrhal  type  the  sac  becomes  somewhat 
thickened  and  distended.  There  is  considerable  ten- 
derness on  pressure  and  the  sac  is  fuller  than  normal. 
By  deep  pressure  a  mucosecretion  can  be  pressed  out 
through  the  puncta,  though  if  the  duct  is  free,  that  is, 
if  there  is  no  stenosis,  it  may  be  pressed  downward 
through  the  duct.  In  the  purulent  type  the  sac  be- 
comes very  greatly  distended,  and  is  exceedingly  tender 
upon  pressure.  The  outlet  of  the  duct  is  usually  oc- 
cluded and  the  tears  flow  over  the  cheek  (epiphora). 
If  not  early  treated  the  case  takes  on  the  appearance 
of  an  abscess,  and  the  wall  of  the  sac  ruptures  and 
the  pus  finds  an  exit  through  the  skin  at  a  dependent 
portion.  Oftentimes  a  permanent  fistula  is  the  result 
of  this  condition. 

57 


58  OPHTHALMOLOGY  FOR  VETERINARIANS 

If  the  case  is  at  the  point  of  rupture  an  incision 
should  be  made,  and,  under  a  local  anesthetic,  the  sac 
may  be  cureted  and  a  solution  of  nitrate  of  silver  applied. 
It  is  well  to  establish  the  drainage  canal  if  possible,  and 
pass  through  it  a  solution  of  argyrol,  then  some  boric 
acid  solution.  Keep  the  sac  clean  and  free  from  pus. 
Should  it  become  permanently  or  chronically  affected, 
the  best  thing  to  do  is  carefully  to  dissect  out  the  sac. 
This  should  be  done  during  the  stage  of  quiescence. 

Stenosis  of  the  Nasal  Duct. — This  almost  always  ac- 
companies the  above  disease,  and  is  due  to  thickening 
and  adhesion  of  the  mucous  lining  of  the  duct.  In 
man,  the  duct  is  probed  from  above,  through  the  puncta 
— usually  the  lower  one.  The  point  of  the  probe  is 
passed  into  the  punctum  in  a  vertical  position,  then, 
placed  horizontally,  it  is  pushed  through  the  canaHculus 
to  the  bony  wall,  then,  again  in  a  vertical  position,  it  is 
gently  pushed  until  it  engages  in  the  upper  portion  of 
the  duct,  when  it  is  forced  firmly,  but  gently,  downward 
through  the  duct.  In  the  animal,  the  probes  used  are 
much  larger  and  longer  than  those  used  in  man,  and, 
instead  of  being  inserted  from  above,  they  are  inserted 
in  the  outlet  of  the  duct  below,  opposite  the  middle 
turbinate  bone  in  the  nose.  After  the  point  of  the  probe 
is  engaged  it  is  pushed  upward  to  the  sac,  gently  break- 
ing up  the  adhesions  in  its  course.  This  operation 
should  be  repeated  two  or  three  times  a  week,  accord- 
ing to  the  indications. 


CHAPTER  VI 

MUSCLES  OF  THE  EYEBALL 

The  muscles  that  move  the  eyeball  are  known  as  the 
extrinsic  muscles.  In  the  animal  they  are  seven  in 
number— the  superior  rectus,  the  inferior  rectus,  the 
external  rectus,  the  internal  rectus,  the  superior  obUque, 
the  inferior  obHque,  and  the  retractor.  This  last  muscle 
is  not  present  in  man. 

All  of  these  muscles,  except  the  inferior  obHque,  have 
their  origin  at  the  apex  of  the  orbit,  near  the  margin  of 
the  optic  foramen.     The  recti  muscles  pass  forward  in 
their  respective  positions,  and  are  inserted  into  the  outer 
surface   of   the   sclerotic   coat.     The   superior   oblique 
passes    through    a   pulley,    near    the    internal    angular 
process  of  the  frontal  bone,  at  which  place  the  muscle 
assumes  a  rounded,  tendinous  formation;  from  there  it 
passes  in  an  external  direction,  expands,  and  is  inserted 
into   the   sclerotic  between   the   superior  and   external 
recti.    The  inferior  oblique  arises  from  the  orbital  plate 
of  the  superior  maxillary,  passes  externally,  and  is  in- 
serted into  the  sclerotic  near  the  superior  obHque,  poste- 
rior to  the  equator.    Both  of  these  muscles  pass  beneath 
the  recti  in  their  course  horizontally. 

The  distance  of  the  insertion  of  the  muscles  from  the 

59 


6o 


OPHTHALMOLOGY  FOR  VETERINARIANS 


corneal  margin  depends  upon  the  animal  and  the  size 
of  the  eye.    In  man  the  recti  muscles  are  inserted  from 


Fig.  21. — Rjght  eye  of  horse:  a,  Remnants  of  periorbita;  b,  levator  pal- 
pebrae  superioris;  c,  obliquus  oculi  inferior;  d,  rectus  oculi  inferior;  e, 
rectus  oculi  externus;  /,  rectus  oculi  superior;  g,  sclera;  g',  cornea;  h, 
lacrimal  gland;  i,  frontal  nerve;  k,  frontal  artery;  /,  branch  of  lacrimal 
nerve  to  gland;  ni,  lacrimal  artery;  n,  zygomatic  nerve;  o,  branch  of 
ophthalmic  artery;  p,  branch  of  oculomotor  nerve  to  obliquus  oculi  in- 
ferior; q,  maxillary  nerve;  r,  infra-orbital  nerve;  s,  posterior  nasal  nerve; 
^,  great  palatine  nerve;  2/,  small  palatine  nerve;  v,  internal  maxillary  ar- 
tery; 'ty,  buccinator  artery  (cut);  .v,  infra-orbital  artery;  .v',  malar  artery; 
)>,  sphenopalatine  artery;  G,  great  palatine  artery;  z',  small  palatine  (or 
staphyline)  artery;  i,  posterior  deep  temporal  artery;  2,  j,  stumps  of 
orbital  margin;  4,  facial  crest;  5,  temporal  fossa;  6,  foramen  lacerum 
orbitale;  7,  anterior  end  of  alar  canal;  8,  posterior  opening  of  same. 
(After  Ellenberger,  in  Leisering's  Atlas.) 

7  to  7^  mm.  from  the  cornea,  while  the  oblique  muscles 
are  inserted  much  farther  back — about  17  to  18  mm. 


AFFECTIONS  OF  THE  MUSCLES  6l 

The  action  of  the  muscles  are  as  follows:  The  external 
and  internal  recti  cause  the  eyeball  to  move  outward 
and  inward  respectively,  and  they  balance,  so  to  speak, 
the  horizontal  movements.  The  superior  rectus  causes 
an  upward  and  shghtly  inward  movement,  while  the 
inferior  rectus  causes  a  downward  and  inward  movement. . 
The  obhque  muscles  cause  the  eyeball  to  rotate  on  its 
anteroposterior  axis.  They  oppose  or  balance  the 
movements  of  the  superior  and  inferior  recti. 

The  retractor  is  the  largest  and  most  powerful  muscle 
of  the  eyeball.  It  has  its  origin  in  common  with  the 
recti  muscles,  surrounding  the  optic  foramen,  passes 
forward,  completely  encasing  the  optic  sheath,  expand- 
ing in  a  funnel  shape,  and  is  inserted  into  the  posterior 
third  of  the  sclerotic  coat.  Its  function  is  to  pull  the  eye- 
ball backward. 

The  insertion  of  the  muscles  are  tendinous,  and  these 
tendons  are  ensheathed  in  a  fascia,  which  is  in  reality 
a  portion  of  Tenon's  capsule. 

All  the  extrinsic  muscles,  except  the  superior  ob- 
hque and  the  external  rectus,  are  supplied  by  the  third 
cranial  nerve.  The  superior  obhque  is  supphed  by  the 
fourth  cranial  nerve,  and  the  external  rectus  by  the 
sixth  cranial  nerve. 

Affections  of  the  Muscles 
In  man  we  have  many  affections  of  the  muscles,  be- 
cause the  eyes  are  so  placed  to  produce,  in  a  normal  case, 


62  OPHTHALMOLOGY  FOR  VETERINARIANS 

perfect  binocular  vision;  hence,  refractive  errors,  causing 
a  greater  effort  to  see,  particularly  close  objects,  tend  to 
produce  a  weakness  of  one  or  more  of  the  extrinsic 
muscles,  resulting  in  a  turning  outward  or  inward  of  a 
few  degrees  of  one  or  both  eyes.  The  condition  is  hardly 
noticeable,  though  it  is  brought  out  by  certain  forms  of 
examination. 

This  may  go  on  and  on  until  the  position  is  easily 
seen  by  a  second  person,  and  the  eye  assumes  the  ap- 
pearance of  being  crossed.  He  may  be  able  to  see  with 
either  eye  singly  and  normally,  but  the  eye  that  is  cov- 
ered, or  not  fixing,  turns  outward  or  inward,  as  the  case 
may  be.  He  may  be  wholly  dependent  upon  one  eye, 
and  the  eye  that  is  not  used  becomes  partially  blind 
(amblyopic) . 

This  is  not  so  in  the  animal,  because  of  the  position 
of  the  eyes  and  numerous  other  reasons.  A  cross-eyed 
animal  is  seldom  ever  seen.  They  may,  however,  be 
subject  to  paralysis  of  the  muscles,  by  reason  of  pressure 
upon  or  disease  of  the  nerves  supplying  those  muscles, 
the  same  as  in  man. 

One  needs  only  remember  the  anatomic  relations,  ac- 
tion, and  nerve  supply  to  determine  which  muscle  and 
nerve  is  involved. 

Ophthalmoplegia.— This  is  a  condition  in  which  all 
the  muscles  are  paralyzed.  There  being  no  resistance, 
the  eyeball  stands  out  prominently  from  the  orbit  and 
is  immobile.     The  Hd  may  droop  (ptosis)  because  of 


AFFECTIONS  OF  THE  MUSCLES  63 

paralysis  of  the  -levator  palpebrae.  There  is  little  that 
can  be  done  except  to  protect  the  cornea;  look  for  the 
cause  and  remove  it  if  possible.  Usually  the  trouble 
is  in  the  brain  at  the  nerves'  nuclei.  When  extensive, 
other  symptoms  of  cerebral  affection  accompany  it. 


CHAPTER  VII 

DISEASES  OF  THE   CONJUNCTIVA 

Conjunctivitis  is  an  inflammation  of  the  con- 
junctiva. It  may  occur  as  a  simple  congestion  of  the 
membrane  or  be  accompanied  by  edema  of  the  tissue, 
with  or  without  secretion,  varying  in  character.  It  may 
be  acute,  subacute,  or  chronic  in  its  nature,  and  occur 
with  inflammation  of  other  portions  of  the  eye. 

Acute  Catarrhal  Conjunctivitis. — In  mild  cases  the 
conjunctiva  of  the  lids  only  is  affected,  while  in  more 
profound  cases  the  whole  conjunctiva  is  involved,  and 
presents  a  bright  red  appearance,  with  enlarged  vessels 
radiating  on  the  globe.  The  swelHng  of  the  tissue  is 
often  intense  toward  the  tarsal  fold  and  the  inner  angle. 
In  some  cases  small  hemorrhagic  spots  occur  which  may 
be  isolated.  These  may  remain  so,  though  they  not 
infrequently  coalesce,  forming  large  patches.  There 
is  an  increased  lacrimal  secretion  at  first,  which  later 
changes  to  a  mucopurulent  character.  In  consequence 
of  this  the  inner  canthus  is  constantly  moist.  The  secre- 
tion may  flow  over  the  lids  and  create  an  irritation  of  the 
skin  and  the  formation  of  crusts.  In  the  morning  the 
lids  are  usually  stuck  together  and  the  lashes  are  matted 

64 


DISEASES  OF  THE  CONJUNCTIVA  65 

with  the  secretion.    If  allowed  to  continue,  it  causes  an 
inflammation  of  the  margin  of  the  lids  and  a  loss  of  the 

lashes. 

As  a  rule,  there  is  not  much  pain— unless  a  foreign 
body  is  present— but  there  is  a  tendency  to  keep  the 
eyes  closed  because  of  the  sensitiveness  to  light.  Itch- 
ing is  an  almost  constant  symptom  at  first,  and  the 
animal,  in  attempting  to  stop  it,  rubs  its  head  against 
some  object,  which  irritates  the  eye  and  makes  matters 
worse. 

The  subacute  type  follows  the  acute,  and,  if  not 
properly  treated,  lapses  into  the  chronic  stage. 

The  causes  are  numerous,  though  the  principal  one  is 
infection  or  the  introduction  of  bacteria.  Anunals  may 
get  into  their  eye  such  substances  as  chaff,  seeds,  dust, 
insects,  hair,  etc.,  or  the  eye  may  be  struck  with  a 
whip  or  twig.  Bacteria  may  extend  to  the  eye  from  the 
presence  of  catarrh  and  other  affections  of  the  nasal 
tract.  Strong  gases,  smoke,  glaring  Kght,  hot  air,  cold 
drafts,  filthy  and  damp  stabling,  and  a  loss  of  health 
generally  may  cause  it.  It  often  accompanies  in- 
fluenza, pneumonia,  glanders,  and  other  diseases  affect- 
ing the  mucous  tracts,  and  in  such  cases  the  same  or- 
ganism causing  these  diseases  causes  the  conjunctivitis. 
Diagnosis. — The  extreme  redness  of  the  conjunctiva, 
together  with  secretion,  the  presence  of  pupillary  reac- 
tion, normal  tension,  and  a  clear  cornea  will  serve  to 
exclude  other  conditions. 


66  OPHTHALMOLOGY  FOR  VETERINARIANS 

Treatment. — The  main  indication  in  all  cases  is  to  find 
the  cause  and  get  rid  of  that.  First  examine  the  eye 
carefully  for  the  presence  of  a  foreign  body.  This  may 
be  found  in  many  cases  only  by  the  closest  inspection 
with  condensed  light  and  a  magnifying  lens. 

If  the  secretion  is  purulent  in  character  a  smear  should 
be  made,  and  this  examined  with  the  microscope  to  de- 
termine what  particular  organism  the  inflammation  is 
due  to.  If  the  eye  is  sensitive  to  light,  the  cornea  should 
be  examined  for  excoriations  of  the  epithelium. 

The  general  condition  should  always  be  cared  for  and 
the  eye  kept  as  clean  as  possible.  In  mild  cases  a  solu- 
tion of 

Sulphate  of  zinc gr.  j ; 

Boric  acid gr-  xx; 

Distilled  water §  j. 

Mix. 

is  sufficient  if  dropped  into  the  eye  several  times  a  day. 
If  the  case  is  a  severe  one  the  conjunctival  surface  may 
be  brushed  Hghtly  with  a  2  per  cent,  solution  of  silver 
nitrate,  and  immediately  washed  off  with  a  normal  salt 
solution  or  clear  water.  If  no  corneal  complications 
exist,  cold  applications  are  indicated.  Strong  Hght 
should  be  excluded  and  the  animal  allowed  to  exercise 
after  sundown. 

Chronic  conjunctivitis  may  follow  the  acute  type,  and 
often  exists  a  long  time.  The  conjunctiva  is  somewhat 
thickened,  and  the  secretion  is  scanty  and  of  a  mucoid 


DISEASES  OF  THE  CONJUNCTIVA  67 

character,  and  is  deposited,  in  conjunction  with  the 
secretion  of  the  meibomian  glands,  at  the  angle  of  the 
Hds.  In  some  cases  there  is  no  secretion  and  the  mem- 
brane is  reddened  and  dry.  When  this  is  the  case 
increased  winldng  occurs  in  order  to  moisten  the  cornea. 
Winking  may  be  increased  also  when  there  is  a  thick- 
ened secretion,  to  free  the  cornea  of  the  mucoid  fila- 
ments which  stick  over  the  pupillary  area  and  interfere 
with  vision.  These  filaments  may  also  form  in  folds  and 
act  as  a  foreign  body  in  the  eye.  The  Hds  become  heavy 
and  drowsy  in  appearance.  The  secretion  upon  the 
margin  of  the  lids  may  produce  a  blepharitis.  At  this 
stage  loose  lashes  drop  out,  and  find  their  way  into  the 
eye  by  rubbing  it  against  some  object  to  reheve  the  itch- 
ing and  burning  sensation.  The  lower  Kd  is  often  de- 
pressed or  everted  and  the  tears  flow  over  the  cheek, 
because  the  lower  punctum  is  drawn  away  from  the 
globe. 

This  type  is  often  seen  in  animals  that  are  in  poor 
health.  Pasturing  in  low  and  damp  lands  is  said  to 
cause  it  even  in  young  foals.  Dust,  wind,  smoke,  and 
irritating  gases  are  common  causes.  It  is  often  asso- 
ciated with  skin  diseases  about  the  head  and  face. 
Duane  says,  ' 'Usually  the  chronic  form  of  conjunctivitis 
(in  man)  is  that  produced  by  the  diplococcus  of  Morax- 
Axenfeld.  There  may  be  very  little  injection  of  the 
conjunctiva,  no  swelhng  of  the  latter,  and  little  or  no 
secretion."      On  the  other  hand,  the  writer  has  seen 


68  OPHTHALMOLOGY  FOR  VETERINARIANS 

several  cases  of  conjunctivitis  caused  by  this  organism 
which  were  of  a  severe  purulent  type.  This  shows  that 
even  in  the  eye  there  is  a  difference  in  the  degree  of 
virulence  of  bacteria  of  the  same  kind. 

The  treatment  is  practically  the  same  as  in  acute 
conjunctivitis.  If  little  or  no  secretion  exists,  a  solution 
of  alum  or  zinc  sulphate  in  about  \  of  i  per  cent, 
acts  favorably,  or  the  conjunctiva  may  be  gently  rubbed 
with  the  alum  stick  every  day  or  two.  Zinc  sulphate 
is  a  specific  in  conjunctivitis  caused  by  the  Morax- 
Axenfeld  bacillus.  Glycerin  tannate  brushed  over  the 
conjunctiva  is  desirable  in  some  cases.  If  crusts  form 
about  the  margin  of  the  lids,  apply  the  yellow  oxid  of 
mercury  ointment  every  night,  and  wash  it  off  the  next 
morning  with  a  solution  of  bicarbonate  of  soda.  This 
will  soften  the  crusts,  when  they  can  be  more  easily 
removed.  It  also  prevents  the  Hds  from  sticking  to- 
gether, and  allows  the  secretion  to  flow  out,  if  there  is 
any.  The  general  health  must  be  taken  into  considera- 
tion, and  any  unhygienic  condition  of  the  stable  or 
pasture  must  be  corrected. 

Purulent  conjunctivitis  is  also  known  as  purulent 
ophthalmia,  and  in  many  cases  resembles  an  acute 
catarrhal  conjunctivitis,  accompanied  with  more  edema 
of  the  conjunctiva  and  an  excess  of  purulent  secretion. 

It  is  caused  by  a  variety  of  pyogenic  organisms,  but 
the  more  common  cause  in  man  is  an  infection  with 
gonorrheal   pus,   when   it   is   spoken   of   as   gonorrheal 


DISEASES  OF  THE   CONJUNCTIVA  69 

ophthalmia.  Law  says,  ''Moller  records  a  widespread 
epidemic  of  gonorrheal  ophthalmia  in  dogs  in  Berlin 
and  environs  in  1883."  As  a  rule,  animals  seem  to  be 
exempt  from  infection  of  the  gonorrheal  pus  of  man, 
though  Frohner  succeeded  in  infecting  the  eye  of  a  dog 
from  such  a  source.  Horses,  dogs,  cattle,  sheep,  and 
swine  are  susceptible  to  purulent  ophthalmia. 

Crowded  and  filthy  conditions  are,  as  a  rule,  the 
cause,  and  if  pyogenic  organisms  find  their  way  into  the 
eye  the  chances  are  a  purulent  conjunctivitis  will  follow, 
as  there  is  no  better  medium  for  the  development  of  such 
bacteria. 

Cases  may  be  sporadic,  though  epidemics  occur 
among  animals  in  closely  crowded  quarters.  One  ani- 
mal may  be  the  cause  of  the  infection  of  a  whole  herd, 
as  hundreds  of  cattle  have  been  attacked  in  a  few  days 
through  the  introduction  of  one  case  among  them. 

In  cases  of  the  so-called  "enzootic  ophthalmia" 
animals  are  said  to  be  exempt  from  succeeding  attacks, 
probably  from  an  estabKshed  immunity. 

The  symptoms,  at  first,  resemble  an  acute  catarrhal 
conjunctivitis,  but  soon  the  true  nature  of  the  case  is 
manifest  by  the  presence  of  pus,  which  is  thin  and 
mucoid  at  first,  but  later  it  becomes  thick  and  greenish- 
yellow  in  color.  The  swelling  of  the  conjunctiva  and 
lids  is  often  so  intense  that  it  is  difficult  to  separate  the 
Hds  sufficiently  to  examine  the  eye  properly. 

If  the  disease  is  not  controlled  the  corneal  epithelium 


70  OPHTHALMOLOGY  FOR  VETERINARIANS 

becomes  softened  by  maceration  and  erosion,  and  ul- 
ceration of  the  cornea  follows.  The  bacteria  may  burrow 
into  the  deep  structure  of  the  eye,  causing  inflammation 
of  these  parts  and  probably  the  loss  of  the  eye. 

Treatment. — CleanUness  and  antiseptic  applications 
are  the  principal  indications.  First  wash  the  eye  with 
a  saturated  solution  of  boric  acid,  then  drop  in  a  25  per 
cent,  solution  of  argyrol.  In  a  few  minutes  wash  this 
out  and  carefully  remove  the  shreds  of  pus  which  the 
solution  has  coagulated.  Then  apply  another  drop, 
and  allow  it  to  remain.  Repeat  this  operation  every 
three  or  four  hours  or  oftener  if  necessary.  After  the 
secretion  has  been  controlled,  use  a  weaker  solution  less 
often  applied.  A  2  per  cent,  solution  of  silver  nitrate 
brushed  over  the  everted  Hds,  and  immediately  washed 
off,  is  of  benefit  in  many  cases.  If  this  is  used,  one  ap- 
pHcation  a  day  is  sufficient.  If  there  is  much  swelling 
of  the  lids  an  ice-cold  application,  frequently  repeated,  is 
of  value.  It  should  not  be  allowed  to  remain  long 
enough  to  become  warm,  for,  in  that  case,  it  acts  as  a 
poultice,  and  encourages  the  growth  of  the  bacteria. 
If  the  cornea  is  involved,  hot  applications  should  be 
used.  Encourage  the  animal  to  keep  the  eye  open  as 
much  as  possible  to  prevent  corneal  complications.  This 
can  be  accompHshed  to  a  great  degree  by  isolating  it  in 
a  clean,  darkened  stall,  and  frequently  cleansing  the  eye 
of  the  secretion,  which  causes  a  reflex  closure  of  the  lids. 

When  one  eye  only  is  affected,  the  other  eye  should 


DISEASES  OF  THE  CONJUNCTIVA  71 

be  protected  with  a  pad  after  it  has  been  thoroughly 
cleansed  with  an  antiseptic  solution. 

Conjunctivitis  during  attacks  of  cow-  and  sheep-pox 
is  due  to  the  same  pathologic  conditions  that  exist  in  the 
skin.  This  t}^e  is  most  virulent.  The  Hds  are  extremely 
swollen  and  the  secretion  is  usually  profuse.  The  char- 
acteristic lesions  on  the  conjunctiva  tend  to  coalesce, 
forming  a  large  area  of  ulceration.  If  it  is  not  early 
controlled  it  may  terminate  in  ulceration  of  the  cornea, 
perforation,  and  loss  of  the  eye. 

The  treatment  is  the  same  as  for  purulent  conjuncti- 
vitis, together  with  that  for  ulceration  of  the  cornea. 

Phlyctenular  Conjunctivitis.— This  is  vesicular  erup- 
tion of  the  conjunctiva,  and  often  accompanies  eczema 
and  other  skin  affections.  The  vesicles  vary  in  size 
from  a  pin-point  to  a  pin-head  or  larger.  They  may 
be  single  or  multiple.  A  favorite  site  is  near  the  corneal 
margin.  They  often  invade  the  cornea,  when  it  is  known 
as  a  phylctenular  keratitis.  The  vesicles  contain 
a  semifluid  of  yellowish  appearance,  said  to  be  due  to 
the  presence  of  staphylococci,  but  late  investigators 
show  that  tubercular  infection  may  be  the  cause.  The 
apex  of  the  vesicles  break  down,  when  they  may  ter- 
minate in  resolution  or  ulceration. 

One  afflicted  with  phlyctenular  disease  of  the  cornea 
or  conjunctiva  shows  typic  symptoms  in  many  cases. 
There  is  much  photophobia,  and  strong  contraction  of 
the  muscle  closing  the  eye,  and  the  head  is  carried  in 


72  OPHTHALMOLOGY  FOR  VETERINARIANS 

a  bowed  position.  The  phlyctenules  have  a  grayish  or 
yellowish  appearance,  and  are  often  suppHed  with  numer- 
ous blood-vessels  branching  toward  them.  As  the  dis- 
ease occurs  principally  in  scrofulous  subjects,  we  often 
have  malnutrition,  enlarged  lymphatics,  eczematous 
crusts  about  the  nose  and  ears,  and  blepharitis  margin- 
alis  with  crust  formation.  In  very  mild  cases  most  of 
these  are  absent,  and  only  a  mild  irritation  of  the  eye 
is  noticeable. 

As  many  of  the  mild  cases  seem  to  be  caused  by  errors 
of  diet,  a  regulation  of  this  alone  will  often  effect  a  cure. 
In  all  cases  of  malnutrition  suitable  tonics  should  be 
given  to  tone  up  the  system.  Skin  affections  should  be 
appropriately  treated.  Mild  antiseptic  colleria  may  be 
used,  and  when  ulceration  has  taken  place  the  yellow 
oxid  of  mercury  ointment  is  of  great  benefit  applied 
three  times  a  day. 

Trachoma. — This  disease  is  principally  confined  to 
man,  though  monkeys  are  subject  to  it.  It  was  known 
in  the  far  eastern  countries  centuries  before  the  time  of 
Christ.  It  is  the  disease  which  at  the  present  time 
checks  foreign  immigration,  and  close  inspection  is 
made  of  the  eyes  of  all  immigrants  before  landing  on 
our  shores.  Some,  no  doubt,  escape  detection,  for  it 
prevails  principally  among  the  foreign  population,  nota- 
bly Hungarians,  Italians,  and  the  lower  class  of  Jews. 
It  is  often  seen  in  persons  of  a  higher  class.  It  is  one 
of  the  diseases  that  causes  a  large  percentage  of  blindness. 


DISEASES  OF   THE   CONJUNCTIVA  73 

It  is  no  doubt  due  to  some  form  of  bacterium  which 
has  not  yet  been  definitely  settled  upon.     The  writer 
has  recently  examined  several  cases  by  culture  growth 
under    the    strictest    precautions,  and   found  a    bacilli 
resembling   the   Klebs-LofHer    in    nearly   all    their  pe- 
cuharities.      The   disease   is   said  to  be   contagious  by 
some,  but  this  is  doubted  by  others.     It  attacks  the 
scrofulous,  debihtated,  and  otherwise  poorly  nourished, 
though  the  writer  has  seen  it  in   those  who  are  well 
nourished,  lead  outdoor  lives,  and  have  sanitary  homes. 
It  is  confined  principally  to  the  palpebral  conjunctiva, 
and  usually  involves  both  eyes.     The  initial  symptoms 
are  much  like  those  of  a  catarrhal  conjunctivitis,  and 
in  many  cases  the  disease  is  well  advanced  before  the 
patient  is  aware  of  its  real  nature.     A  secrerion  is  de- 
veloped of  a  mucopurulent  character  and  folHcles  are 
numerous.    These  resemble  sago  grains,  and  are  confined 
to  the  lymphoid  structure.    They  eventually  break  down, 
discharge,  and  cicatrize  while  others  are  forming.     A 
gritty  feeling  is  experienced  in  the  act  of  winking,  and, 
by  reason  of  this   and  an  extension  of  the  disease,  the 
upper  part  of  the  cornea  becomes  irritated  and  inflamed. 
This  is  known  as  pannus.    The  thickened  rissue  produces 
a  shght  drooping  of  the  lid.    When  the  conjunctiva  is 
exhausted  by  extensive  ulceration  and  cicatrization  a 
degree  of  contracrion  takes  place,  and  the  border  of  the 
lid  is  drawn  inward,  producing  an  entropion.     This  is 


74  OPHTHALMOLOGY  FOR  VETERINARIANS 

more   so   when   the   tarsus  is   involved.     The   disease 
usually  becomes  chronic. 

Treatment. — To  obtain  the  best  results  treatment 
should  be  commenced  early  in  the  disease.  If  the  fol- 
licles are  full  and  numerous  the  radical  treatment  is 
the  best.  This  consists  of  an  expression,  or  squeezing 
out,  of  the  follicle  contents  with  a  Knapp's  or  Prince's 
forceps.  The  conjunctiva  is  then  scrubbed  with  a  solu- 
tion of  corrosive  sublimate  of  i  :  looo  or  even  i  :  500 
parts,  and  then  washed  with  distilled  water.  Iced  anti- 
septic applications  for  twenty-four  hours  will  allay  the 
reaction.  When  the  conjunctiva  has  recovered,  and 
there  is  a  tendency  to  recur,  it  may  be  rubbed  lightly 
every  second  day  with  a  crayon  of  sulphate  of  copper. 
If  the  secretion  persists,  argyrol  in  25  per  cent,  solution 
may  be  used,  appHed  every  three  or  four  hours,  or  silver 
nitrate  in  2  per  cent,  solution,  used  as  in  purulent 
conjunctivitis. 

Cleanliness  and  freedom  from  secretion  are  the 
indications,  together  with  stimulation  to  enhance 
resolution.  Boric  acid,  aristol,  calomel,  etc.,  are  used 
as  dusting-powders  and  also  in  the  form  of  ointments. 
The  x-ray  has  been  employed  with  benefit. 

Follicular  conjunctivitis  resembles  an  ordinary  catar- 
rhal conjunctivitis,  with  follicles  in  the  retrotarsal  fold 
and  in  the  fornix.  They  are  arranged  in  clusters  or 
rows  parallel  to  the  Hd  margin.  It  is  principally  con- 
fined to  the  young,  is  said  to  be  infectious,  and  appears 


DISEASES  OF  THE  CONJUNCTIVA  75 

periodically.  Some  physicians  make  no  distinction 
between  this  disease  and  true  trachoma,  but  it  is,  with- 
out doubt,  a  distinct  disease.  It  responds  readily  to 
simple  treatment,  while  trachoma  is  most  obstinate. 

Xerosis  of  the  conjunctiva  is  a  dry  condition,  and  is 
due  to  the  action  of  a  bacterium  known  as  the  xerosis 
bacillus.  It  is  a  short  bacillus,  often  appears  in  pairs, 
end  to  end,  sometimes  broader  at  one  end,  and  in  many 
cases  resembles  the  Klebs-Loffler  bacillus. 

The  disease  attacks  those  suffering  from  malnutrition. 
It  is  scarcely  seen  in  robust  animals.     It  accompanies 
other  diseases— trachoma— and  is  nearly  always  pres- 
ent in  wasting  diseases,  near  the  point  of  death,  and  in 
old  and  poorly  fed  beasts.     It  extends  to  the  whole 
surface  of  the  conjunctiva  and  both  eyes  are  involved. 
There  is  a  scanty  secretion  of  a  foamy  nature  deposited 
upon  the  margin  of  the  Hds  and  at  their  angles.    This 
secretion  contains  the  baciUi  in  large  numbers.     The 
character  of  the  secretion,  the  dryness  of  the  conjunc- 
tiva, and  the  loss  of  briUiancy  to  the  cornea— which 
has  a  duU,  greasy  appearance— are  the  principal  symp- 
toms. 

As  the  disease  accompanies  malnutrition,  suitable 
tonics  and  a  supply  of  sufficient  food  of  a  proper  quahty 
should  be  given.  When  it  occurs  with  other  diseases 
of  the  conjunctiva  these  should  be  met  with  proper 
treatment.  In  wasting  diseases  the  condition  is  beyond 
repair,  and  death  only  relieves  the  victim. 


76  OPHTHALMOLOGY  FOR  VETERINARIANS 

Membranous  Conjunctivitis. — This  occurs  in  both 
man  and  beast.  Fowls  are  particularly  susceptible  to  it. 
It  not  only  attacks  the  eye  of  the  fowl,  but  also  the 
mucous  tract  of  the  nose,  mouth,  and  throat.  This 
condition  in  the  fowl  is  known  by  the  common  name  of 
''roup,"  and  is  allied  to  diphtheria  in  the  human  family. 
The  membrane  is  grayish- white,  and  in  some  cases  is  of 
a  thick,  yellowish,  cream  color.  It  is  usually  thick  and 
tough,  strongly  adherent,  invades  the  deep  structures, 
and  extends  to  the  sinus  about  the  orbit.  The  fowl  is 
Kstless,  often  standing  with  its  head  drooped  and  un- 
conscious of  its  surroundings.  When  the  general  sys- 
tem becomes  invaded  with  the  toxemia,  the  fowl  refuses 
to  eat  or  drink  and  much  loss  of  weight  takes  place.  If 
the  eyeball  becomes  involved,  as  it  often  does,  the  loss 
of  the  organ  follows.  The  membrane  is  so  profuse  as  to 
protrude  between  the  lids,  and  in  one  case  the  writer 
saw  it  perforated  the  upper  lid,  producing  a  large  cica- 
trix after  healing.  It  is  said  to  attack  choice  varieties 
of  fowls  particularly. 

Cats,  calves,  and  sheep  are  susceptible  to  diphtheritic 
infection.  There  are  forms  of  bacteria  resembling  so 
closely  the  true  Klebs-Lofifler  bacillus  it  is  with  difficulty, 
and  only  by  certain  biologic  tests  or  characteristics, 
they  can  be  differentiated.  In  1884  Lofifler  described 
two  special  types  in  animals — the  Bacillus  diphtheriae 
columbrarum  and  the  Bacillus  diphtheriae  vitulorum. 
The  former    he    obtained  from    the  pseudomembranes 


DISEASES  OF  THE  CONJUNCTIVA  77 

''in   the  mouths  of  pigeons,   dead  from  an  infectious 
form  of  diphtheria  which  prevailed  in  some  parts  of 
Germany   among   these   birds    and    among   chickens." 
The  latter  he  obtained  ''from  the  pseudomembranous 
exudation  in  the  mouths  of  calves  suffering  from  an 
infectious  form  of  diphtheria."     Because  these  organ- 
isms differ  in  many  respects  from  the  true  Klebs-LofHer 
bacillus,  it  does  not  indicate  that  they  are  less  dangerous 
to  man.    We  believe  that  this  and  many  other  diseases 
are  imparted  to  the  human  being  through  the  lower 
animals.     For  this  reason,  pet  animals,  when  suffering 
with   diseases  of   the   eyes  of   a  membranous  nature, 
should  be  isolated  from  children,  for  these  are  the  very 
parts  handled  and  stroked  by  their  innocent  hands,  and 
they   unconsciously    become    infected  by  wiping  their 
own  eyes.    The  result  may  be  a  severe  conjunctivitis  of 
the  child's  eyes,  possibly  the  loss  of  an  eye,  or  even  the 
loss  of  Hfe.    Law  quotes  several  cases  of  infection  of  the 
human  being  from  fowls  suffering  with  membranous 
conjunctivitis.     "Four  attendants  contracted  the  dis- 
ease from  sick  fowls  at  a  time  when  no  other  cases 
existed  in  the  human  population.    Diphtheria  prevailed 
in  fowls,  and  soon,  also,  in  those  who  fed  them.     A 
diphtheritic   chicken  conveyed   the   disease  with   fatal 
effect  to  a  child  which  fondled  it." 

With  this  and  other  testimony  in  favor  of  the  con- 
tagiousness of  membranous  affections  of  the  conjunctiva 
of  chickens,  it  is  best  to  isolate  them  from  the  rest  of  the 


78  OPHTHALMOLOGY  FOR  VETERINARIANS 

flock,  and  also  from  members  of  the  household,  especially 
children. 

There  is  a  stage  of  exfoliation  in  which  much  of  the 
membrane  can  be  easily  removed;  but  if  this  cannot  be 
done  without  causing  bleeding  of  the  tissues  beneath 
it  should  not  be  attempted.  Numerous  remedies  have 
been  recommended.  Corrosive  sublimate  solution  in 
I  :  2000  or  even  i  :  looo  parts  has  been  used  without 
injury  to  the  cornea.  Carbolic  acid  in  suitable  strength 
or  a  saturated  boric  acid  solution  is  of  value.  Some 
use  kerosene  oil  with  good  results.  Antitoxin  has 
been  used  satisfactorily.  Give  the  chicken  soft  foods 
or  milk,  as  grain  causes  irritation  of  the  mucous  tracts 
if  the  membrane  has  extended  to  the  mouth  and  throat. 
With  an  ordinary  chicken  the  best  course  to  pursue  is 
to  cut  its  head  off  and  bury  it,  but  with  a  prize  chicken 
of  great  value  it  is  a  different  proposition. 

Pinguecula. — ^This  is  a  slight  elevation  of  the  con- 
junctiva or  subconjunctival  tissue,  just  a  few  milli- 
meters from  the  internal  border  of  the  cornea.  It  was 
formerly  supposed  to  be  a  fatty  growth,  hence  its  name. 
It  is  reddish-yellow  in  color,  and  at  times  becomes 
inflamed,  when  it  causes  much  discomfort.  Just  what 
its  cause  is  no  one  seems  to  know.  Errors  of  refrac- 
tion, dust,  and  strong  wind  are  supposed  to  be  the 
cause. 

When  in  a  quiescent  state  they  are  not  troublesome, 
but  when  inflamed  they  are  very  annoying.    Astringent 


DISEASES  OF  THE  CONJUNCTIVA  79 

colleria  are  beneficial.     If  persistent  they  may  be  ex- 
cised. 

Tuberculosis  of  the  Conjunctiva.— This  appears  ordi- 
narily in  the  form  of  ulcers  in  the  palpebral  conjunctiva, 
though  it  may  spread  to  the  conjunctiva  of  the  globe 
and  even  to  the  cornea.  The  ulcerated  surfaces  are 
covered  with  grayish-red  granulations,  about  which 
are  numerous  nodules.  The  whole  Hd  becomes  affected 
in  severe  cases. 

The  disease  may  be  primary  and  only  affect  one  eye, 
though  it  often  accompanies  or  leads  to  general  infection. 
The  neighboring  lymphatics  are  usually  involved.  The 
cause  is  local  infection,  and  it  is  nearly  always  confined 
to  the  young. 

Excision  of  the  ulcers,  followed  by  the  use  of  the 
actual  cautery,  is  the  best  treatment.  Iodoform,  in 
powder  or  ointment,  is  of  value,  and  good  results  have 
followed  the  injection  of  tuberculin. 

Pterygium— This  is  an  encroachment  of  the  con- 
junctiva of  the  globe  upon  the  cornea.  Its  usual  site  is 
at  the  inner  margin.  It  may  be  unilateral  or  bilateral. 
The  growth  extends  in  some  cases  over  the  pupillary 
area.  It  is  said  to  arise  from  a  pinguecula  and  expo- 
sure to  strong  winds. 

As  a  rule  it  is  not  inconvenient,  unless  it  has  made 
much  progress  over  the  cornea,  when  symptoms  of  irri- 
tation and  traction  occur.  The  vascularity  and  thicken- 
ing of  the  tissue  are  usually  great,  though  in  some  cases 


So  OPHTHALMOLOGY  FOR  VETERINARIANS 

the  growth  is  extremely  thin  and  only  slightly  vascular. 
If  much  traction  is  made  the  movement  of  the  eyeball 
is  interfered  with,  and  astigmatism  may  result  or  even 
diplopia. 

The  true  pterygium  is  loosely  adherent  except  at 
the  apex,  and,  being  folded  in  upon  itself  at  the  corneal 
margin,  a  probe  may  be  passed  beneath  it  to  the  fold  at 
this  point.  This  serves  to  distinguish  it  from  a  false 
pterygium— one  caused  by  injury.  The  latter  is  strongly 
adherent  all  along  its  course. 

The  only  thing  to  do  is  to  excise  them.  There  are 
several  methods,  but  the  simplest  one  is  as  follows: 
Grasp  the  apex  of  the  growth  with  a  delicate  forceps,  and 
dissect  it  carefully  to  the  corneal  margin;  then  make  a 
V-shaped  excision  of  the  pterygium^the  apex  of  the  V 
toward  the  inner  canthus.  Undermine  the  conjunctiva 
so  that  the  remaining  edges  can  be  drawn  together  by 
sutures,  using  care  that  it  does  not  overlap  the  cornea. 
Precede  the  operation  with  the  usual  antiseptic  precau- 
tions and  two  or  three  applications  of  a  5  per  cent, 
solution  of  cocain.    Some  cases  recur. 

Foreign  Bodies  in  the  Conjunctiva  and  Cornea. — 
Vegetable  substances  are  commonly  found  in  the  folds 
of  the  conjunctiva,  such  as  seeds,  particles  of  hay,  barbs 
from  grain  heads,  etc.  The  writer  saw  a  small  seed  which 
had  caught  in  the  conjunctiva,  had  become  covered 
with  mucus,  and,  when  removed,  was  in  a  state  of  ger- 


DISEASES  OF  THE  CONJUNCTIVA  8i 

mination.     Chips  or  twigs  of  wood,  bits  of  stone,  and 
grit  are  often  found  in  the  eyes  of  animals. 

Pain  with  increased  lacrimation,  redness  of  the  con- 
junctiva, and  sensitiveness  to  Hght  are  the  principal 
symptoms.  If  the  body  is  located  on  the  conjunctiva 
of  the  upper  lid  the  act  of  winking  brings  it  in  contact 
with  the  sensitive  cornea  and  causes  increased  pain. 
The  tears  flow  over  the  cheek  because  there  is  a  greater 
quantity  secreted  than  the  little  ducts  can  take  care  of. 
If  allowed  to  remain,  the  cornea  becomes  irritated  and 
scratched,  and  ulceration  of  this  body  may  arise.  If 
the  foreign  body  is  on  the  cornea  the  conjunctiva  of  the 
upper  lid  becomes  irritated  and  inflamed  by  reason  of 
the  friction,  and  a  catarrhal  or  purulent  conjunctivitis 
may  follow. 

The  nictitans  membrane  is  a  wise  provision  for  the 
spontaneous  removal  of  foreign  bodies  and  the  protec- 
tion of  the  anterior  portion  of  the  eye.  The  retractor 
muscle  acts  as  a  protector  from  advancing  injury  by 
drawing  the  eyeball  backward.  The  lashes  have  the 
function  of  catching  dust  and  small  objects  that  would 
otherwise  enter  the  eye  and  cause  inflammation. 

Treatment. — The  principal  object  in  treatment  is  to 
find  the  foreign  body  and  remove  it.  This  should  be  ac- 
compHshed  with  some  degree  of  nicety.  If  it  cannot  be 
readily  seen,  evert  the  lower  lid  by  making  traction 
downward  with  the  thumb.  If  it  is  still  not  seen,  grasp 
the  upper  lashes  with  the  thumb  and  index-finger,  and 


82  OPHTHALMOLOGY  FOR  VETERINARIANS 

place  the  index-finger  of  the  other  hand,  or  a  probe, 
about  midway  between  the  margin  and  the  upper  por- 
tion of  the  Hd,  as  a  fulcrum,  and  lift  the  lid  upward. 
This  will  evert  the  lid  and  it  can  easily  be  inspected. 
If  a  foreign  body  be  seen,  wet  with  an  antiseptic  solu- 
tion a  small  piece  of  cotton,  and,  after  squeezing  out 
the  excess  of  fluid,  wipe  away  the  body.  Sometimes  the 
foreign  body  may  become  lodged  in  the  retro  tarsal  fold; 
in  such  cases  make  a  small  swab  by  twisting  a  piece 
of  cotton  on  the  end  of  a  probe,  wet  this  and  sweep 
it  under  this  portion  of  the  hd,  when  it  will  be  dislodged. 
The  foreign  body  may  be  hidden  in  the  folds  about  the 
inner  canthus  and  nictitans  membrane,  when  only  the 
most  careful  search  will  reveal  it. 

When  a  foreign  body  is  on  or  embedded  in  the  cornea 
it  requires  the  most  careful  treatment.  First,  try  a 
small  piece  of  cotton,  well  twisted  and  free  from  loose 
fibers,  and  quickly  wipe  over  the  body,  when,  m  many 
cases,  it  will  become  caught  in  the  cotton  and  removed. 
It  if  cannot  be  readily  removed  by  this  method,  use  a  5 
per  cent,  solution  of  cocain,  and  with  a  small  knife- 
needle  gently  prick  about  the  body  and  remove  it, 
doing  as  Httle  damage  to  the  corneal  epithelium  as  pos- 
sible. If  the  epithelium  is  much  roughened  by  this 
operation,  smooth  it  gently  with  an  eye  spatula  or  the 
smooth,  rounded  portion  of  a  shell  spoon.  Of  course, 
strict  antisepsis  must  be  observed  in  all  cases.  The 
writer  has  seen  severe  corneal  ulcers  and  loss  of  vision 


DISEASES  OF  THE  CONJUNCTIVA  S^ 

from  the  careless  removal  of  foreign  bodies  from  the 

cornea. 

Bums  of  the  Conjunctiva  and  Cornea.— Horses  at- 
tending fire  engine  companies,  those  used  in  warfare, 
and  anunals  confined  within  burning  buildings  are  liable 
to  receive  direct  burns  from  firebrands,  explosions,  etc. 
Chemical  burns  are  caused  by  strong  corrosives,  such 
as  lime  and  acids,  splashed  into  the  eye. 

According  to  the  degree,  the  symptoms  vary  from  a 
mild  redness  of  the  conjunctiva  to  a  complete  exfoHa- 
tion  of  this  tissue.    It  may  be  confined  to  a  small  area 
or  engage  the  whole  conjunctiva  and  cornea.    Pain  is 
always  present.    In  some  cases  the  conjunctiva  is  gray- 
ish-white  in   color,    particularly   during   the   stage   of 
sloughing.     The  cornea  is  nearly  always  involved  in 
severe  cases,  and  becomes  opaque,  like  ground  glass  in 
appearance,  and  the  return  to  its  normal  transparency 
depends  upon  the  depth  of  the  bum.    The  subsequent 
effects  of  a  burn  of  the  conjunctiva  and  cornea  are  al- 
ways to  be  dreaded,  although  the  immediate  symptoms 
may  not  appear  to  be  profound.    For  this  reason  one 
should  be  guarded  in  his  prognosis.    Adhesions,  either 
partial  or  complete,  may  take  place  between  the  con- 
junctiva of  the  lid  and  that  of  the  globe,  causing  lunited 
motion.    The  cornea  also  may  be  permanently  opaque 
and  blindness  follow. 

As  the  pain  at  first  is  intense,  a  drop  of  a  5  per  cent, 
solution  of  cocain  appHed  to  the  conjunctiva,  with  ice- 


84  OPHTHALMOLOGY  FOR  VETERINARIANS 

cold  compresses  over  the  lid,  will  allay  it  sufficiently  to 
make  an  examination.  Carefully  remove  any  foreign 
substances  and  flush  the  eye  with  sterile  water  or  boric 
acid  solution.  If  the  burn  is  caused  by  a  strong  caustic, 
neutralize  it  with  a  suitable  solution.  OHve  oil,  with  the 
alkaloids  of  atropin  and  cocain,  are  of  value  in  relieving 
pain,  putting  the  accommodation  to  rest,  and  prevent- 
ing adhesions  by  allowing  the  hd  to  play  more  freely  over 
the  globe  in  the  act  of  winking.    An  adhesion  (symbleph- 


Fig.  2  2. — Dermoid  cyst  from  original  specimen. 

aron)  may  be  prevented  to  a  great  degree  by  daily 
breaking  it  with  a  small  blunt  probe.  If  extensive  ad- 
hesions occur,  surgical  treatment  is  necessary. 

Tumors  of  the  Conjunctiva.— These  are  benign  and 
malignant.  The  former  interfere  with  the  function  of 
the  eye  by  pressure.  The  latter  usually  cause  the  loss 
of  the  eyeball,  and  may  endanger  life  by  extension. 

The  principal  benign  tumors  are  polypi,  cysts,  lipomata, 
and  granulomata. 

A  polypus  is  a  pear-shaped  tumor,  pale  and  red  in 


DISEASES  OF  THE  CONJUNCTIVA  85 

color,  bleeds  easily  by  friction,  and  is  found  usually  in 
the  region  of  the  caruncle. 

A  cyst  may  arise  as  the  result  of  an  injury,  or  ''may 
form  from  dilated  blood-vessels  or  lymph-vessels,  or 
from  the  sac  of  a  cysticercus  cellulosse."  A  type  of 
cyst  sometimes  seen  at  the  junction  of  the  cornea  is 
called  a  dermoid  cyst,  and  is  always  congenital  (Fig.  22.) 

A  lipoma,  or  fatty  tumor,  is  a  congenital  growth,  and 
is  seen  under  the  conjunctiva,  usually  in  the  upper  and 
outer  portion. 

A  papilloma,  or  warty  growth,  is  more  frequently 
seen  springing  from  the  margin  of  the  conjunctiva  and 

A  granuloma,  known  commonly  as  "proud  flesh,"  is 
the  result  of  traumatism,  and  usually  springs  from  the 
point  of  injury.  It  is  often  seen  at  the  mouth  of  a  sinus, 
and  should  not  be  confounded  with  a  pathologic  growth. 
It  is  simply  an  excess  of  healthy  tissue  and  may  be  ex- 
cised. 

The  principal  malignant   tumors   are   the   sarcomata 

and  carcinomata. 

A  sarcoma  may  grow  from  any  point  of  the  conjunc- 
tiva, but  usually  the  seat  is  near  the  margin  of  the  cornea. 
It  bleeds  easily  because  of  its  great  vascularity,  and  is 
often  pigmented. 

A  carcinoma,  or  cancer,  is  not  infrequently  seen  in  the 
region  of  the  above  tumor.  It  becomes  papillomatous  in 
its  appearance  and  is  devoid  of  pigment.    In  course  of 


86  OPHTHALMOLOGY  FOR  VETERINARIANS 

time  its  malignancy  is  marked  and  destructive  processes 
ensue. 

The  treatment  of  all  tumors  is  a  complete  excision  of 
all  the  tissue  involved.  The  malignant  types  often  re- 
quire an  enucleation  of  the  eyeball,  and  in  some  cases 
all  the  tissues  in  the  orbit  must  be  removed  (exentera- 
tion). 

Inflammation  of  the  Nictitans  Membrane.— This 
occurs  often  in  conjunction  with  conjunctivitis,  though 
it  may  occur  without  inflammation  of  adjacent  struc- 
tures. The  membrane  may  be  only  slightly  inflamed, 
or  it  may  become  severely  inflamed,  swollen,  and 
edematous  to  such  an  extent  as  to  completely  cover  the 
cornea.  It  is  usually  due  to  traumatism.  It  often 
becomes  chronically  hyper trophied,  which  greatly  in- 
terferes with  its  function  and  the  closure  of  the  lids,  and 
when  the  advancement  is  very  great  it  covers  the  pupil- 
lary area  and  shuts  off  vision. 

The  excision  of  this  body  should  be  the  last  thing 
resorted  to.  Keep  the  eye  clean  with  antiseptic  and 
astringent  washes  and  use  antiseptic  ointment  for 
lubrication.  Be  particular  to  examine  the  body  care- 
fully for  foreign  bodies  which  may  be  lodged  within 
its  folds  or  beneath  it.  Hot  appHcations  every  two  or 
three  hours  are  beneficial,  followed  by  astringent  col- 
leria.  If,  after  diligent  treatment,  the  body  remains 
hyper  trophied,  that  portion  externally  may  be  excised, 
being  careful  to  leave  that  part  of  it  that  sweeps  over  the 


DISEASES  OF  THE  CONJUNCTIVA  87 

cornea,  together  with  the  muscles  that  control  it.  After 
such  an  operation  contraction  readily  takes  place,  and, 
as  a  rule,  it  resumes  its  normal  size.  In  cases  of  edema 
only  several  punctures  in  the  outer  portion  allows  the 
escape  of  serum.  This  should  be  followed  by  cold 
applications  frequently  appHed. 

Edema  of  this  body,  together  with  the  conjunctiva  of 
the  globe,  is  often  symptomatic  of  some  remote  trouble, 
such  as  purulent  inflammation  of  the  orbital  tissues  or  the 
hidden  sinuses.  In  the  former  case  there  is  more  or  less 
proptosis  or  bulging  of  the  globe. 

The  membrane  is  sometimes  drawn  over  the  cornea 
spasmodically  in  cases  of  tetanus. 


CHAPTER  VIII 

DISEASES  OF  THE   CORNEA 

The  cornea  is  one  of  the  most  important  structures 
of  the  globe.  It  is  perfectly  transparent,  and  is  one  of 
the  refractive  media  next  in  importance  to  the  lens. 
Diseases  of  this  body,  resulting  in  opacity,  cause  a 
greater  percentage  of  blindness  than  diseases  of  all 
other  portions  of  the  eye  combined. 

It  is  composed  of  five  layers,  and  a  knowledge  of  these 
layers  (see  Anatomy),  with  the  ability  to  distinguish 
the  seat  of  the  disease,  will  assist  one  materially  in  his 
prognosis. 

Keratitis  is  an  inflammation  of  the  cornea.  It  may 
be  local  and  confined  to  a  small  area,  or  it  may  be  general, 
involving  the  whole  corneal  structure.  Superficial 
keratitis,  in  which  the  epithelium  only  is  involved,  may 
undergo  complete  repair,  with  much  damage  to  the  re- 
fractive value.  When  Bowman's  membrane  is  destroyed 
it  is  never  replaced.  When  localized  destruction  of  the 
true  corneal  layer  occurs  it  is  filled  in  by  cicatricial  tissue 
quite  different  in  arrangement  from  normal  elements. 

In  severe  types  of  keratitis  there  is  also  a  congestion 
of  the  conjunctiva,  and  often  an  inflammation  of  the  iris 

88 


DISEASES  OF  THE   CORNEA  89 

and  ciliary  body,  with  an  exudate  in  the  anterior  cham- 
ber. This  exudate  may  be  purulent  in  character,  when 
it  is  called  a  hypopyon.  The  amount  varies  from  a 
slight  hne,  which  can  barely  be  seen,  to  a  complete 
filling  of  the  chamber.  The  consistence  of  this  exudate 
also  varies  from  a  thin,  watery  fluid  to  a  thick,  pultaceous 
mass.  The  former  is  readily  absorbed,  while  the  latter 
may  undergo  a  fibrinous  change  and  cause  adhesions  be- 
tween the  iris  and  the  cornea. 

Small  spots  of  infiltration  and  superficial  nebulae 
can  readily  be  detected  by  the  use  of  obhque  illumination 
and  a  magnifying  lens.  Dense  opacities  can  easily  be 
seen  without  these  means.  In  a  recent  infiltration  there 
is  a  dull  and  clouded  appearance  over  the  area.  In 
case  of  an  ulcer  there  is  a  loss  of  substance,  seen  in  mild 
cases,  by  a  break  in  a  reflected  line  on  the  surface  of  the 
cornea.  If  the  surface  retains  its  luster  the  ulcer  is  a 
clean  one,  but  if  there  is  a  cloudiness  over  its  area,  it  is 
a  foul  or  infected  one.  An  opacity  with  a  lustrous 
surface  indicates  an  old  ulcer  which  has  healed  in,  leav- 
ing a  cicatrix. 

The  symptoms  of  keratitis  are  essentially  the  same 
in  all  types.  Pain,  lacrimation,  and  photophobia  are 
nearly  always  present.  Reflex  contraction  of  the  lid 
(blepharospasm)  is  a  common  symptom,  except  in  those 
cases  caused  by  paralysis  of  the  fifth  and  seventh  nerves. 
In  the  former  case  there  is  no  pain. 

Keratitis   is   divided   into   two   principal   types— the 


go  OPHTHALMOLOGY  FOR  VETERINARIANS 

suppurative  and  the  non-suppurative.  The  suppurative 
includes  all  ulcers,  and  those  forms  which  are  induced 
by  infection  from  without.  The  non-suppurative  type 
includes  pannus,  the  vesicular  and  punctate  forms, 
interstitial  and  all  forms  of  keratitis,  which  are,  as  a 
rule,  caused  by  constitutional  disease. 

Ulcer  of  the  Cornea. — As  the  cornea  is  the  most  ex- 
posed portion  of  the  eye,  an  ulcer  is  one  of  its  most  com- 
mon affections.  Ulcers  range  in  degree  from  the  sim- 
plest form,  minute  in  size,  to  the  destruction  of  a  large 
area  of  corneal  tissue,  and  their  course  is  influenced,  to  a 
great  degree,  by  the'  organism  causing  the  ulcer,  its 
early  treatment,  and  the  constitutional  resistance. 

Simple  ulcers  begin  with  a  small  infiltration,  which 
eventually  breaks  down.  They  are  usually  clean,  though 
they  may  have  a  slight  grayish  base.  They  may  be  ir- 
regular in  shape,  though  usually  circular.  They  have, 
under  proper  treatment,  a  tendency  to  heal  readily 
without  advancing. 

In  severe  types  the  inflammation  extends  backward 
into  the  deep  structures  or  spreads  over  a  large  area  in 
the  anterior  layers.  Deep  ulceration  may  invade  the 
whole  thickness  of  the  cornea.  When  perforation  takes 
place  there  is  a  loss  of  aqueous  with  a  prolapse  of  the 
iris  into  the  wound.  This  remains  impacted,  and  be- 
comes adherent  at  the  point  of  prolapse.  At  this  stage 
resolution  usually  begins,  and  there  is  a  gradual  filling 
in  or  restoration  of  tissue,  later  marked  by  the  presence 


DISEASES  OF  THE  CORNEA  91 

of  a  cicatrix  or  scar,  which  is  opaque.  If  the  perforation 
is  not  over  the  pupillary  area  it  does  not  materially  in- 
terfere with  vision  except  by  traction  upon  the  iris 
over  the  point  of  prolapse,  which  causes  a  dislocated 
pupil  to  the  point  of  prolapse  or  adhesion.  If  per- 
foration occurs  over  the  pupillary  area  a  permanent 
fistula  may  be  the  result,  or  the  anterior  capsule  of  the 
lens  may  be  drawn  into  the  wound  and  an  adhesion 
takes  place.  An  opacity  then  occurs  at  this  point  which 
interferes  with  vision  very  greatly,  as  it  is  directly  in  the 
central  field. 

Causes. — Traumatism  is  the  most  common  cause, 
such  as  the  presence  of  a  foreign  body  or  the  careless 
removal  of  one,  followed  by  infection;  scratching  the 
cornea  by  a  twig  or  whip;  a  misdirected  eyelash;  a  burn, 
or  an  injury  which  breaks  the  epithelium  and  carries 
infection  with  it,  or  later  becomes  infected.  Infection 
is  the  ultimate  cause  of  all  corneal  ulcers.  When  free 
from  infection  much  mechanical  injury  of  the  cornea 
may  be  done  without  purulent  inflammation  following. 
Exposure  keratitis,  followed  by  ulceration,  may  be 
primarily  caused  by  lagophthalmus,  exophthalmus,  and 
paralysis  of  the  fifth  nerve.  Purulent  diseases  of  the 
conjunctiva  and  lacrimal  apparatus,  cow-pox,  in- 
fluenza, and  other  infectious  diseases  are  common 
causes.  The  streptococcus,  staphylococcus,  pneumo- 
coccus,  and  other  pyogenic  bacteria  are  the  infecting 
agents. 


92  OPHTHALMOLOGY  FOR  VETERINARL\NS 

Some  types  of  ulcers  are  more  severe  than  others; 
they  have  special  characteristics  and  are  known  by 
special  terms. 

The  crescentic  ulcer  occurs  near  the  Hmbus  or  sclero- 
corneal  margin,  and  from  its  location  is  also  known  as 
marginal  keratitis.  It  begins  as  an  interrupted  Hne  of 
infiltration  beneath  the  epithelium.  Small  pustules  arise 
along  its  course,  which  coalesce.  The  epithelium  soon 
breaks  down  and  a  continuous  ulcer  results.  As  a  rule 
it  is  confined  to  the  superficial  layers  and  may  spread  to 
the  center  of  the  cornea,  leaving  in  its  wake  a  thin  cica- 
trix. It  may  terminate  favorably  in  a  few  days,  though 
its  progress  is  often  protracted,  and  months  may  elapse 
before  recovery  takes  place.  It  most  frequently  occurs 
in  the  aged. 

The  Serpiginous  Ulcer. — This  is  one  of  the  most 
destructive  types  of  sloughing  ulcer.  It  is  character- 
ized by  a  grayish-yellow  disk-like  patch,  centrally 
located,  with  an  opacity  about  the  border  and  somewhat 
elevated.  Numerous  radiating  striae  invade  the  corneal 
surface;  the  anterior  layers  break  down  and  eventually 
a  large  ulcerated  area  filled  with  pus  results.  There  is 
usually  much  pain  connected  with  it  in  and  about  the 
eye,  though  in  some  cases  the  pain  is  not  so  intense  as 
the  pathologic  process  would  lead  one  to  believe  it 
might  be.  Iritis  and  iridocycKtis  with  hypopyon  very 
frequently  occur.  In  many  cases  the  ulcer  perforates 
the  cornea,   allowing  the  escape  of  aqueous  and  pus. 


DISEASES  OF  THE  CORNEA  93 

The  pus  in  the  anterior  chamber  does  not  come  from  the 
cornea,  but  from  the  inflamed  condition  of  the  struc- 
tures within  the  globe.    When  perforation  takes  place 
the  severity  of  the  central  portion  subsides,  though 
destruction  of  the  tissue  may  proceed  along  the  borders 
until  the  whole  cornea  has  become  destroyed.     Per- 
foration is  followed  with  a  prolapse  of  the  posterior  struc- 
tures; the  iris  falls  into  the  opening,  or,  if  exactly  central, 
the  lens  capsule  may  fill  the  perforation  and  become 
adherent.    After  perforation,  healing  takes  place  much 
more  quickly,   though   there   is   a  scar  left  which  is 
opaque  and  interferes  with  vision.    In  extremely  severe 
types  purulent  inflammation  of  the  uveal  tract  occurs, 
the  eye  is  lost,  and  shrinking  of  the  globe  follows. 

A  purulent  ulcer  is  any  ulcer  which  rapidly  or  slowly 
sloughs.  It  is  due  to  the  entrance  of  pyogenic  bacteria 
following  an  injury  to  the  cornea.  The  progress  invades 
the  deep  corneal  layers  at  the  point  of  commencement 
and  a  rapid  destruction  of  the  tissue  follows.  Early 
treatment  should  be  employed  in  order  to  save  the  eye. 
Hypopyon  is  pus  in  the  anterior  chamber.  It  gravi- 
tates to  the  lowest  portion  of  the  chamber;  and  if  fluid 
in  character  it  changes  its  position  upon  movements 

of  the  head. 

Trealmenl  of  Corneal  ?7fcm.-The  treatment  of  all 
ulcers  of  the  cornea  must  be  prompt,  and  energetic 
measures  employed.  If  the  ulcer  is  a  small  one  and 
apparently  clean,  simple  antiseptic  washes  maybe  used, 


94  OPHTHALMOLOGY  FOR  VETERINARIANS 

followed  by  the  yellow  oxid  of  mercury  ointment  to 
promote  healing.  One  of  the  best  mild  antiseptic  washes 
is  the  saturated  solution  of  boric  acid  with  a  little 
astringent  added.  Zinc  sulphate  is  usually  employed 
for  this  purpose  in  the  strength  of  |  to  i  grain  to  the 
ounce. 

If  the  ulcer  is  a  foul  one,  that  is,  filled  with  purulent 
matter,  the  object  in  treatment  is  to  kill  the  bacteria 
causing  it,  and  at  the  same  time  to  prevent  its  advance- 
ment. Cure  ting  the  ulcer  to  the  healthy  tissue  was 
formerly  employed,  and  in  some  cases  is  a  valuable  pro- 
cedure if  done  by  experienced  hands ;  but  much  care  must 
be  used,  or  more  damage  than  good  will  be  done  by  the 
use  of  the  curet.  One  of  the  best  cleansing  agents  is  one 
of  the  new  silver  salts,  either  argyrol  or  protargol,  from 
lo  to  50  per  cent,  solution.  It  is  well  to  use  the  stronger 
solution  at  first,  gradually  reducing  the  strength  as  one 
gets  results.  This  should  be  dropped  into  the  eye, 
and  soon  washed  away  with  the  purulent  matter  which 
the  silver  salt  has  coagulated.  This  operation  can  be 
repeated  every  one,  two,  or  three  hours,  according  to  the 
severity  of  the  case;  between  times  wash  the  eye  freely 
and  frequently  with  a  saturated  solution  of  boric  acid. 

If  the  ulcer  does  not  respond  to  this  treatment,  but 
rather  increases  in  size  and  depth,  touch  it  slightly  with 
the  strong  tincture  of  iodin.  As  this  is  exceedingly  pain- 
ful, it  should  be  preceded  by  the  application  of  a  5  to  10 
per  cent,  solution  of  cocain  dropped  on  the  cornea. 


DISEASES  OF  THE  CORNEA  95 

Sharpen  a  matchstick  or  wooden  toothpick,  wind  a  small 
piece  of  cotton  on  this  so  that  it  will  point  sharply 
beyond  the  point  of  the  stick,  dip  it  in  the  iodin  tincture, 
but  do  not  have  so  much  on  the  cotton  that  it  will  drop 
or  run.  Hold  the  lids  well  open,  and  paint  the  surface 
of  the  ulcer,  using  care  that  none  touch  the  other  por- 
tions of  the  cornea.  Keep  the  Hds  open  a  short  time 
until  the  alcohol  has  evaporated.  This  operation  may 
be  repeated  every  two  or  three  days  if  necessary.  Most 
admirable  results  have  followed  this  method  of  treat- 
ment. The  writer  has  used  iodin- vasogen  in  place  of  the 
tincture  of  iodin  in  some  cases  with  good  results. 

In  place  of  the  iodin,  or  in  conjunction  with  it,  after 
the  immediate  irritation  has  subsided,  powders  may  be 
dusted  into  the  eye.  Iodoform  is  one  of  the  best,  either 
in  full  strength  or  mixed  with  equal  parts  of  fine  boric 
acid.  This  fills  the  ulcer,  destroys  bacteria,  absorbs 
secretion,  and  has,  to  some  extent,  an  anesthetic  effect. 
When  powders  are  used  in  the  eye,  the  finest  quality, 
free  from  lumps  and  foreign  matter,  should  be  selected. 
They  may  be  used  in  a  powder-blower  or,  better,  dip 
a  camels'  hair  brush  into  the  fine  powder,  hold  it  in  front 
of  the  eye  between  the  thumb  and  second  finger,  and 
give  it  a  quick  strike  with  the  index-finger,  which  will 
cause  the  powder  to  fly  into  the  eye.  Aristol  and 
calomel  are  sometimes  used  in  these  cases. 

Antiseptic  and  stimulating  ointments  are  of  much 
benefit  after  the  sloughing  process  has  subsided.    Among 


96  OPHTHALMOLOGY  FOR  VETERINARIANS 

the  best  of  these  are  the  yellow  oxid  of  mercury  ointment, 
4  to  8  grains  to  the  ounce,  or  the  red  iodid  of  mercury 
ointment,  i  grain  to  the  ounce.  In  all  ointments  for  the 
eye  the  drug  should  be  well  incorporated  with  the  base, 
and  ground  evenly  and  smoothly,  as  the  smallest  free 
particle  of  the  drug  will  produce  much  irritation,  the 
same  as  a  foreign  body.  Iodoform  is  often  used  in  the 
form  of  an  ointment  in  strength  of  from  2  to  25  per  cent. 
The  base  is  often  made  of  vaselin  alone,  but  equal  parts 
of  vaseHn  and  lanohn  are  better.  In  applying  the 
ointments,  place  a  piece  about  the  size  of  a  pea  on  the 
everted  lower  lid  and  draw  the  upper  hd  over  it,  after 
which  use  gentle  massage  over  the  closed  lids.  Oint- 
ments of  standard  strengths  are  now  put  up  by  supply 
houses  in  tube  containers  which  are  very  convenient. 

Heat  is  always  indicated  in  ulcer  of  the  cornea.  This 
is  best  applied  by  pieces  of  cotton  wrung  out  in  boiling 
water  and  placed  over  the  closed  Hds,  as  hot  as  they  can 
be  borne  by  the  hand.  In  acute  cases  this  should  be  done 
every  hour  or  two,  and  before  using  other  treatment. 

Atropin  should  always  be  used  if  the  ulcer  is  centrally 
located,  but  if  it  be  near  the  margin  of  the  cornea  a 
myotic  is  indicated. 

The  eye  should  be  protected  with  a  pad,  and  if  the 
ulcer  is  a  deep  one  a  pressure  bandage  should  be  used. 

When  rupture  of  the  cornea  seems  inevitable  the  best 
method  is  to  hasten  it  by  a  Saemisch  operation.  This  is 
done  by  passing  the  point  of  a  Von  Graefe  cataract 


DISEASES  OF  THE  CORNEA  97 

knife  through  the  healthy  cornea  near  the  margin  of  the 
ulcer,  pass  it  along  horizontally  in  the  anterior  chamber, 
and  cause  the  point  to  emerge  through  the  healthy  cornea 
near  the  opposite  margin,  cutting  forward  through  the 
ulcer.  This  can  be  done  under  local  anesthesia.  Atropin 
should  be  used,  so  that  the  iris  will  not  prolapse  into  the 
wound.  This  operation  at  once  reduces  the  tension  if 
there  be  any,  and  allows  the  escape  of  aqueous  and  pus 
from  the  anterior  chamber.  Under  slight  pressure  and 
the  continued  use  of  atropin  and  antiseptics  resolution 
sets  in  more  readily. 

When  the  pneumococcus,  which  is  said  to  be  the  cause 
of  serpigenous  ulcer,  is  present,  the  antipneumococcic 
serum  has  been  used  with  great  benefit. 

Pannus. — This  is  an  affection  of  the  upper  and  ante- 
rior layers  of  the  cornea,  characterized  by  an  opacity  of 
these  layers,  filled  with  numerous  ramifying  blood-vessels. 

In  mild  types  the  affection  is  superficial  to  Bowman's 
membrane,  but  in  severe  types  this  membrane  is  de- 
stroyed and  the  cornea  proper  becomes  invaded.  It  is 
due  to  friction  of  the  diseased  conjunctival  surface  of 
the  Kd,  more  particularly  to  trachoma,  and  to  an  ex- 
tension of  the  pathologic  process  to  the  layers  of  the 
cornea. 

The  degree  and  rapidity  of  the  disease  may  be  so 
great  as  to  involve  the  whole  upper  surface  of  the  cornea, 
even  encroaching  over  the  pupillary  area,  and  some- 
times covering  the  whole  corneal  surface. 
7 


98  OPHTHALMOLOGY  FOR  VETERINARIANS 

The  characteristic  radiation  of  the  blood-vessels,  its 
location,  together  with  the  presence  of  trachoma,  serve 
to  distinguish  it  from  other  diseases  of  the  cornea. 

When  the  Hds  are  contracted  and  the  palpebral 
fissure  is  lessened  in  consequence,  the  greater  is  the 
liabiHty  of  its  occurrence.  The  superficial  type  readily 
clears  up  under  proper  treatment,  but  the  longer  the 
disease  prevails  and  the  deeper  the  structures  involved, 
the  more  certain  will  there  be  a  permanent  opacity. 

Treatment. — The  main  indications  are  to  relieve  the 
pressure  of  the  Hds  upon  the  cornea,  and  to  treat  the 
trachomatous  disease  of  the  conjunctiva  as  described 
under  that  head.  The  pressure  can  be  relieved  by 
dividing  the  outer  tendon  of  the  orbicularis  muscle  as 
follows:  Pass  the  blunt  end  of  the  blade  of  a  strong 
pair  of  scissors  horizontally  beneath  the  outer  canthus, 
the  other  above,  make  one  quick  snip;  at  the  same  time 
keep  the  parts  stretched  with  the  thumb  and  forefinger 
of  the  other  hand.  If  the  result  is  unsatisfactory, 
divide  the  remaining  strands  with  a  small  pair  of  scissors. 
Bleeding  can  easily  be  stopped  by  compression,  and  the 
wound  heals  rapidly.  This  operation  is  known  as 
canthotomy. 

If  one  desires  to  draw  the  wound  together  to  obtain 
a  permanent  result,  three  sutures  may  be  introduced 
horizontally,  one  through  the  conjunctiva  to  the  ex- 
treme angle  of  the  wound,  the  remaining  two,  one 
above  and  one  below,  at  a  point  midway  between  the 


DISEASES  OF  THE  CORNEA  99 

first  suture  and  the  upper  and  lower  inner  angles  of  the 
wound,  avoiding  the  deep  structures.  This  operation 
is  known  as  canthoplasty. 

The  red  iodid  of  mercury  ointment,  i  grain  to  the 
ounce,  with  a  i  per  cent,  solution  of  atropin,  appHed 
three  times  a  day,  is  of  great  value,  together  with  general 
cleanliness  and  the  treatment  of  the  lids. 

If  much  opacity  of  the  cornea  remain,  treatment  as 
described  under  that  head  may  be  employed. 

Phlyctenular  Keratitis.— This  is  a  vascular  disease, 
and  may  appear  on  any  portion  of  the  corneal  surface, 
but  is  more  often  seen  at  the  limbus  and  associated 
with  phlyctenular  conjunctivitis,  under  which  head  it  is 
described. 

Herpes  Comeae. — This  is  a  form  of  vesicular  keratitis. 
It  usually  occurs  in  conjunction  with  herpes  on  other 
portions  of  the  body  or  face,  such  as  the  lips,  nose, 
forehead,  and  eyelids,  more  especially  when  these 
eruptions  accompany  or  follow  febrile  diseases  of  the 
respiratory  tract,  such  as  influenza,  pneumonia,  bronchi- 
tis, etc.  It  is  characterized  by  a  vesicle— one  or  several— 
which  is  at  first  clear,  but  soon  becomes  cloudy  or  yel- 
lowish in  color,  eventually  breaks  down,  and  forms  a  cor- 
neal ulcer.  Much  pain  and  irritation  attend  it.  The 
prognosis  is  good  if  carefully  treated,  but  if  neglected 
destruction  of  the  cornea  may  occur  by  widespread 
ulceration.     The  treatment  is  principally  symptomatic. 

Herpes  zoster  also  attacks  the  cornea.     It  is  much 


lOO  OPHTHALMOLOGY  FOR  VETERINARIANS 

like  the  former,  though  more  severe  and  protracted  in 
its  course,  and  the  deep  structures  are  more  Hable  to 
become  involved.  One  special  feature  is,  the  cornea  is 
insensitive  to  touch.  Holocain,  in  i  per  cent,  solution, 
dropped  on  the  cornea  every  two  hours,  is  of  great 
value,  together  with  general  symptomatic  treatment. 

Dentritic  Keratitis. — This  is  a  superficial  type  of 
keratitis  characterized  by  branching  processes.  The 
branches  have  the  appearance  of  a  grayish  elevated  Hne 
of  infiltration.  The  epithelium  covering  these  branches 
soon  breaks  down,  forming  slight  furrows.  This  may 
remain  superficial  in  character,  or  it  may  invade  the 
deeper  structures  of  the  cornea  and  result  in  perforation. 
The  disease  is  said  to  be  due  to  malaria,  though  it 
occurs  frequently  quite  independent  of  malarial  in- 
fluence. 

Treatment. — When  malaria  exists  it  should  be  properly 
treated.  Dumb  animals  as  well  as  man  have  this  dis- 
ease. Antiseptic  washes  and  stimulating  ointments, 
together  with  general  treatment,  is  all  that  can  be 
recommended.  The  disease  is  often  very  protracted  in 
its  course  and  seems  to  resist  all  treatment. 

Filamentous  Keratitis.— This  is  characterized  by  a 
mass  of  twisted  thread-like  growths  from  the  corneal 
surface.  They  are  composed  of  epitheHal  cells,  which 
become  elongated  and  have  the  appearance  of  fibrillae. 
They  often  arise  from  the  floor  of  an  ulcer  or  from  an 
abrasion  of  the  epithelium.     The  number  of  the  fila- 


DISEASES  OF  THE  CORNEA  loi 

ments  may  be  few  or  numerous.  They  undergo  mucoid 
degeneration,  and  after  one  crop  disappears,  in  a  few 
days  fresh  crops  appear. 

Treatment. — As  the  disease  occurs  in  debihtated  sub- 
jects, tonic  treatment  as  well  as  local  should  be  used. 
Mild  antiseptic  and  astringent  washes  and  protection 
are  sufficient  in  the  majority  of  cases. 

Desiccation  Keratitis. — This  is  caused  by  want  of 
proper  lubrication  and  protection,  by  failure  of  the  Hd 
to  cover  the  corneal  surface,  due  to  paralysis  of  the 
orbicularis  palpebrarum  muscle,  to  extreme  exophthal- 
mus  or  ectropion.  The  condition  is  confined  to  the 
superficial  layers,  though  in  neglected  cases  the  deep 
layers  become  involved,  including  the  iris  and  cihary 
body. 

Treatment. — When  the  muscle  is  paralyzed,  the  lids 
can  be  brought  together  and  retained  in  that  position 
by  the. aid  of  adhesive  plaster.  This  affords  the  natural 
moisture  to  the  cornea,  and  with  proper  stimulating 
ointments  the  advancement  of  the  disease  can  be 
aborted.  In  the  case  of  extreme  exophthalmus  very 
little  can  be  done  except  to  treat  the  cause  of  the 
proptosis  and  apply  lubricating  ointments  and  oils  to 
prevent  the  cornea  from  becoming  dry.  Ectropion 
must  be  treated  surgically. 

Neuroparalytic  Keratitis. — This  is  much  like  desicca- 
tion keratitis,  except  that  the  former  is  due  to  want  of 
protection,  while  the  latter  is  due  to  insensibility  of  the 


102  OPHTHALMOLOGY  FOR  VETERINARIANS 

cornea  and  adjacent  structures  by  reason  of  disease  of 
the  fifth  nerve.  The  cornea  is  not  sensitive  to  the 
presence  of  dust  and  foreign  bodies,  the  reflex  secretion 
of  the  lacrimal  gland  is  interfered  with,  and  the  act  of 
winking  is  lessened  in  frequency;  hence  the  cornea 
becomes  dry,  the  epithelium  eroded  and  subjected  to 
the  lodgment  and  growth  of  destructive  bacteria,  and 
loss  of  substance  through  ulceration  is  the  result. 

Treatment. — The  treatment  in  this  condition  is 
obvious.  Protection  of  the  cornea  is  the  principal 
indication,  with  the  continuous  use  of  antiseptic  oint- 
ments. If  ulceration  has  taken  place  the  general  treat- 
ment of  ulcers  and  protection  must  be  employed.  The 
cause  of  the  diseased  nerve  must  also  be  looked  for  and 
treated. 

Keratomalacia  or  Xerosis  of  the  Cornea. — This  is  due 
to  dryness  of  the  cornea  in  conjunction  with  xerosis  of 
the  conjunctiva,  under  which  head  it  is  described. 

Staphyloma  of  the  Cornea. — This  is  a  protuberance 
of  the  cornea  produced  by  ulceration,  perforation,  and 
prolapse  of  the  iris.  It  may  be  partial  or  complete;  and 
in  shape  conic  or  hemispheric.  The  spheric  form  is 
more  frequent,  and  includes  a  general  bulging  of  the 
cornea,  forming  a  sharp  outline  from  the  scleral  margin. 
The  wall  of  the  staphyloma  becomes  very  thin  in  places, 
showing  the  iris  pigment,  giving  it  the  appearance  of  a 
bluish  grape.  In  other  instances  the  wall  is  thick  and 
appears  white  or  opalescent.     Numerous  blood-vessels 


DISEASES  OF  THE  CORNEA  103 

may  be  seen  radiating  over  the  surface.  Cicatricial 
bands  form  over  the  point  of  perforation,  causing  a 
special  thickening  of  the  wall  at  that  point.  The  anterior 
chamber  becomes  obHterated,  as  the  iris  is  closely  ad- 
herent to  the  posterior  portion  of  the  cornea. 


Fig.  23. — Staphyloma  of  the  cornea  of  the  human  eye.  Prepared  by 
the  author.  This  condition  was  due  to  trachoma.  To  the  right  of  the 
center  of  the  cornea  is  the  point  of  ulceration  and  perforation,  with  exu- 
dation and  thickening.  To  the  left  the  iris  can  be  seen  glued  to  the 
cornea,  which  is  extremely  thin.    The  light  spot  in  the  center  is  a  bubble. 

A  partial  staphyloma  is  confined  to  one  portion  of  the 
cornea,  is  cone  shaped,  and  has  a  white  apex.  The 
remainder  of  the  cornea  is  clear.  The  iris  is  only  ad- 
herent at  the  point  of  perforation.  This  usually  pro- 
duces dislocation  of  the  pupil,  and,  with  the  irregularity 
of  the  corneal  curvature,  interferes  with  vision. 

Treatment. — As  ulceration  of  the  cornea  is  the  primary 


I04  OPHTHALMOLOGY  FOR  VETERINARIANS 

cause  of  staphyloma,  this  should  be  treated  according 
to  the  rules  under  that  head.  If  the  perforation  occurs, 
a  bandage  should  be  appHed  with  moderate  compres- 
sion, the  bowels  kept  open,  and  any  undue  exertion  pre- 
vented. When  the  staphyloma  is  complete  the  eye  is 
of  no  practical  value,  though  Hght  may  be  perceived. 

If  tension  is  present  in  the  early  stages  a  small  inci- 
sion through  the  cornea,  at  its  margin,  may  be  made, 
which  allows  the  escape  of  the  aqueous,  reduces  the  ten- 
sion, and  encourages  the  reduction  of  the  thin  wall. 
The  eye  should  then  be  protected  with  a  bandage  with 
gentle  pressure.  When  the  eye  has  lost  its  function  by 
reason  of  extreme  staphyloma  an  operation  may  be 
performed  for  cosmetic  purposes,  as  the  condition  is 
very  unsightly;  also  to  allow  the  lids  to  cover  the  globe 
more  completely.  The  operation  according  to  the 
method  of  De  Wecker,  known  as  ablation  or  excision, 
may  be  employed.  The  conjunctiva  is  first  divided 
around  the  limbus,  undermining  it  some  distance  from 
the  margin,  threads  are  then  passed  through  the  upper 
and  lower  portion  of  this  tissue,  so  that  it  may  be 
drawn  together  much  like  the  mouth  of  a  tobacco 
pouch.  The  staphyloma  is  then  abscised,  beginning 
at  the  lower  margin  with  a  cataract  knife  and  finishing 
with  curved  scissors.  Through  the  upper  and  lower 
margins  stitches  are  placed  for  the  purpose  of  drawing 
it  together,  but  before  doing  this  the  lens  is  removed 
after  incising  its  capsule.    The  corneal  sutures  are  then 


DISEASES  OF  THE  CORNEA  105 

drawn  tightly  and  tied,  and  the  whole  covered  by  the 
conjunctiva  by  tightening  and  tying  the  puckering 
threads.  The  excision  should  be  performed  so  as  to  get 
a  transverse  closure  and  as  near  the  center  as  possible, 
to  avoid  irritation  in  the  act  of  winking. 

Keratectasia  is  a  protrusion  of  the  cornea  following 
a  keratitis  without  perforation,  though  the  cornea  has 
become  thin  by  destruction  of  the  superficial  layers 
and  offers  httle  resistance  to  intra-ocular  pressure. 
It  differs  from  a  staphyloma  in  that  the  iris  is  not 

involved. 

An  incision  through  the  cornea  at  the  margin,  followed 
by  a  compress  bandage,  is  of  value,  though  if  tension 
persists  an  iridectomy  should  be  done,  not  to  reduce  the 
tension  alone,  but  for  visual  purposes  as  well. 

Keratoconus,  or  conic  cornea,  resembles  keratecta- 
sia in  some  respects.  It  is  not  due  to  an  inflammatory 
process,  however,  and  does  not  become  opacified.  It 
is  caused  by  a  thinness  of  the  corneal  layers  which 
yield  readily  to  the  pressure  within  the  globe,  causing 
the  cornea  to  assume  a  clear  cone  shape. 

Keratoglobus,  also  called  hydrophthalmus  and  buph- 
thalmus  (ox  eye)  .-In  this  case  there  is  not  a  protru- 
sion of  the  cornea  alone,  as  in  the  preceding  diseases, 
but  rather  an  enlargement  of  the  cornea  in  keeping 
with  the  general  enlargement  of  the  globe.  It  is  con- 
genital, as  a  rule,  or  appears  in  early  life,  and  is  said 
to  be  analogous  to  glaucoma  in  later  life.     The  coats 


I06  OPHTHALMOLOGY  FOR  VETERINARIANS 

of  the  globe  are  thin,  and  the  pigment  can  be  seen 
through  the  sclera,  giving  it  a  bluish  appearance.  The 
tension  is  increased,  and  when  this  subsides  the  dis- 
ease ceases;  but,  if  the  tension  continues,  the  disease  goes 
on  to  ultimate  blindness.     Both  eyes  are  affected.     It 


Fig.  24. — An  extreme  exophthalmos  or  protrusion  of  the  globes, 
more  marked  in  the  left,  due  to  an  abnormal  fatty  growth  in  the  orbits. 
Notice  the  opacity  of  the  cornea  from  exposure. 

is  said  to  be  hereditary,  though  the  exact  nature  and 
cause  of  the  disease  is  not  fully  understood. 

Opacities  of  the  Cornea. — Opacities  are  the  result  of 
ulceration  or  disease  of  the  true  corneal  layer.  They 
may  be  small  or  large,  thin  or  opaque,  according  to  the 
extent  and  depth  of  the  disease. 

Opacities    are    usually    divided    into    three    degrees: 


DISEASES  OF  THE  CORNEA  107 

first,  a  nebula,  which  is  a  slightly  clouded  patch;  second, 
a  macula,  a  somewhat  denser  patch;  and  third,  a  leu- 
koma, a  dense  opalescent  patch. 

If  the  opacity  is  not  over  the  pupillary  area  it  does 
not  materially  interfere  with  the  vision,  but  if  it  be 
centrally  located  vision  of  the  central  field  is  de- 
stroyed. 

Treatment.— As  the  opacity  is  composed  of  cicatricial 
tissue   quite    different    in    structure    from   the   normal 
elements  of  the  cornea,  it  is  impossible  to  reproduce  a 
perfect  transparency,  though  in  some  cases  the  results 
are    surprising   when   proper    treatment   is    employed. 
The  following  remedies  are  useful:  Dionin,  in  solution 
of  5  to  10  per  cent.,  or  in  the  form  of  the  powder,  is 
probably  the  best.    Begin  with  5  per  cent,  solution  and 
drop  into  the  eye  three  to  five  times  a  day.    This  at  first 
produces   an   extreme   reaction,    and   causes   the   con- 
junctiva to  become  very  red  and  edematous.    When  this 
takes  place,  use  it  less  frequently.    The  reaction  subsides 
in  a  day  or  two,  and,  after  using  the  dionin  a  few  times, 
it  ceases  to  have  this  effect,  when  a  stronger  solution 
may  be  employed.     In  conjunction  with  this  use  the 
yellow  oxid  of  mercury  ointment  in  the  eye  three  times 
a  day,  followed  by  massage.    An  ointment  of  thiosinamin, 
10  per  cent.,  is  also  recommended.    The  results  are  due, 
in  great  part,  to  massage  used  with  the  appHcations. 
Massage  alone  has  been  followed  with  excellent  results. 
One  must  have  patience  in  the  treatment  of  opacities,  as 


lo8  OPHTHALMOLOGY   FOR  VETERINARIANS 

it  takes  a  long  time  to  accomplish  any  degree  of  clear- 
ness. When  the  opacity  is  centrally  located,  and  it 
cannot  be  made  clear  by  medication,  an  iridectomy  may 
be  done  for  optical  effect. 

Interstitial  Keratitis. — This  is  also  known  as  paren- 
chymatous keratitis,  keratitis  profunda,  and  keratitis 
diffusa. 

It  is  essentially  a  disease  of  the  young,  and  the  usual 
cause  in  man  is  hereditary  syphihs,  though  it  frequently 
occurs  in  dogs  as  a  result  of  distemper.  It  may  begin  at 
the  center  or  margin  of  the  cornea,  as  a  grayish  macula 
located  in  the  stroma.  This  gradually  extends  until 
the  whole  cornea  becomes  invaded,  and  the  tissues 
become  opaque  and  assume  a  ground-glass  appearance. 
On  close  inspection  vessels  may  be  seen  ramifying 
through  the  deep  layers,  while  some  have  tuft-like 
branches  near  the  margin.  The  disease  is  very  pro- 
tracted in  its  course,  and  one  or  more  months  may 
elapse  before  it  has  reached  its  height,  when  the  severity 
of  the  symptoms  will  gradually  subside,  and  it  may 
then  require  months  before  the  cornea  will  resume  its 
normal  transparency;  and  there  is  a  probability  that  it 
will  never  become  transparent  again.  In  some  cases 
the  disease  is  more  localized  and  confined  to  small 
areas.  As  a  rule  the  vascular  condition  exists  in  pro- 
portion to  the  extent  and  degree  of  infiltration.  There 
are  non- vascular  forms,  however,  in  which  very  few 
vessels   can   be   seen.     Being   confined  to  the   stroma. 


DISEASES  OF  THE  CORNEA  109 

ulceration  does  not  occur,  nor  does  purulent  disintegra- 
tion follow,  as  in  the  superficial  types  of  keratitis. 

The  general  symptoms  of  keratitis  accompany  the 
interstitial  type — viz.,  pain,  lacrimation,  and  photo- 
phobia. In  severe  cases  iritis  and  inflammation  of 
other  portions  of  the  uveal  tract  occur.  The  fellow  eye 
becomes  involved  sooner  or  later,  and  when  syphihs  is 
the  cause  the  knee-joints  may  become  swollen  and 
tender  to  pressure. 

Treatment. — When  caused  by  specific  disease,  consti- 
tutional treatment  must  be  employed.  Locally,  relieve 
the  eye  of  any  undue  irritation  from  strong  light,  etc. 
Atropin  should  be  employed  to  give  the  accommodation 
rest  and  relieve  or  counteract  a  possible  attack  of  iritis. 
Should  iritis  arise,  dionin  may  be  used  in  conjunction 
with  atropin,  and  later  the  yellow  oxid  of  mercury 
ointment  added  to  this  treatment,  to  promote  absorp- 
tion and  assist  in  clearing  the  cornea  of  remaining 
opacities.  Should  conjunctivitis  exist,  as  it  often  does 
in  the  case  of  distemper,  this  should  be  treated  on  gen- 
eral principles. 


CHAPTER  IX 
DISEASES  OF  THE  IRIS  AND  CILIARY  BODY 

The  structure  of  the  iris  is  practically  the  same  in  all 
animals,  though  the  arrangement  of  the  muscle-fibers 
differ  somewhat.  For  example,  the  pupil  of  the  horse 
is  elliptic  horizontally,  while  that  of  the  cat  has  the 
appearance  of  a  vertical  sHt  during  contraction.  The 
corpus  nigra,  suspended  from  the  upper  portion  of  the 
horse's  pupil,  has  the  appearance  of  a  pathologic  tumor. 

The  color  depends  upon  the  amount  of  pigment 
present  in  the  posterior  layers  and  in  the  meshes.  Some 
animals — white  rabbits  for  instance — are  devoid  of 
pigment  and  the  irides  are  of  a  pinkish  color.  In  horses 
this  is  occasionally  seen  as  a  partial  defect,  a  portion 
only  of  the  iris  and  adjacent  structure  appearing  white 
or  pink.  It  is  not  unusual  in  the  human  family  to  see 
persons  with  little  or  no  pigment  in  the  irides,  and  when 
such  is  the  case  the  hair  and  other  portions  of  the  body 
are  lacking  in  this  element.  Such  persons  are  known  as 
''albinos."  An  unequal  amount  of  pigment  in  each 
iris  causes  one  to  look  blue  and  the  other  brown  or 
black. 

110 


DISEASES  OF  THE  IRIS  AND   CILIARY  BODY       iii 

Congenital  defects  of  the  pupil  are  often  noticed,  and 
one  of  the  most  common  is  a  persistent  pupillary  mem- 
brane. It  is  common  in  man,  and  has  been  seen  in  the 
horse,  ox,  dog,  and  rabbit.  Youatt  mentions  a  case 
of  congenital  blindness  from  this  cause  in  a  female 
pointer  eight  weeks  old  (Steel's  ''Diseases  of  the  Dog"). 
''Meyer  notes  the  case  of  a  congenital  double  pupil 
in  a  horse;  a  bridge  extending  across  the  space  from  the 
upper  to  the  lower  border,  and  cutting  off  the  outer 
third  of  the  opening"  (Law's  "Veterinary  Medicine"). 
Ectopia  pupillcB,  or  displacement  of  the  pupil,  is  not 
uncommon,  and  frequently  accompanies  luxation  of  the 
lens.  Colohoma  of  the  iris  is  a  condition  in  which  a  por- 
tion of  the  iris  is  absent  from  the  border  of  the  pupil 
to  the  periphery,  causing  a  large,  irregular  opening. 
Aniridia  is  a  condition  in  which  the  iris  is  absent. 
These  congenital  defects  should  not  be  confounded  with 
pathologic  conditions  following  iritis,  injuries,  etc. 

The  size  and  shape  of  the  piipil  vary  in  different 
animals,  and  are  influenced  by  light,  darkness,  ac- 
commodation, medication,  and  disease. 

Mydriasis,  or  dilatation  of  the  pupil,  is  due  to  paralysis 
of  the  third  nerve,  irritation  of  the  ciHospinal  center, 
constitutional  diseases,  diseases  of  the  central  nervous 
system,  contusions,  intra-ocular  pressure,  and  certain 
drugs  known  as  mydriatics. 

Myosis,  or  contraction  of  the  pupil,  is  caused  by 
paralysis  of  the  cervical  sympathetic,  tabes  dorsalis, 


112  OPHTHALMOLOGY  FOR  VETERINARL\NS 

inflammation  of  the  iris,  foreign  bodies  on  or  in  the  cor- 
nea, and  certain  drugs  known  as  myotics. 

W.  B.  Coakley^  has  noted  pin-point  contraction  of  the 
pupil  as  a  pathognomonic  eye-symptom  in  rabies. 
^'The  contraction  is  so  strong  as  to  resist  the  effect  of 
mydriatics."  He  further  says,  "A  contracted  pupil 
which  yields  to  mydriatics  is  sufficient  to  exclude 
hydrophobia.  There  is  medium  dilation  immediately 
before  death."  In  the  same  article  he  notes  that  ''alco- 
hol, opium,  morphin,  codein,  carbohc  acid,  eserin,  and 
chloral,  all  of  which  contract  the  human  pupil,  were 
given  to  dogs  in  lethal  doses  without  producing  the 
myosis  noted  in  rabbits." 

•  Iritis,  or  inflammation  of  the  iris.  The  iris  is  practically 
an  extension  of  the  anterior  portion  of  the  ciHary  body, 
and  we  will  consider  them  together.  The  relation  of  the 
blood-vessels  and  their  source  must  be  kept  in  mind, 
as  those  of  the  chorioid  cihary  body  and  iris  are  inti- 
mately associated,  and  a  knowledge  of  their  arrangement 
is  necessary  when  we  come  to  consider  inflammation  of 
these  structures,  as  it  is  rather  exceptional  for  the  iris 
to  be  inflamed  when  the  ciliary  body  is  not  more  or  less 
involved. 

An  iritis  may  be  mild  or  severe  in  type.  The  iris  be- 
comes hyperemic,  the  blood-vessels  dilated,  and  a 
change  of  color  from  that  of  the  other  iris  takes  place, 
according    to    the    amount    of    inflammation    present. 

^  Medical  Record,  July  6,  1907. 


DISEASES  OF  THE  IRIS  AND   CILIARY  BODY       113 

This  change  of  color  is  not  as  marked  in  dark-colored 
irides  as  in  those  of  a  hghter  color.  A  bluish  iris  be- 
comes greenish  in  color.  The  iris  loses  its  luster  and  its 
fine  Hnes  are  less  distinct.  If  this  hyperemic  condition 
goes  on  to  a  more  severe  type  of  inflammation,  exuda- 
tion occurs  and  the  iris  becomes  muddy  in  appearance. 
This  exudation  is  composed  of  leukocytes  and  other 
inflammatory  debris  which  settle  to  the  bottom  of  the 
anterior  chamber,  where  it  may  be  seen  as  a  whitish  line, 
and  varies  from  one  barely  visible  to  one  filling  the  cham- 
ber. The  more  of  this  exudate  there  is  present,  the  more 
clouded  the  iris  appears.  Not  infrequently  the  blood- 
vessels rupture,  and  the  blood  settles  in  the  most  de- 
pendent portion  of  the  anterior  chamber,  as  does  the 
exudate.  Blood  in  the  anterior  chamber  is  called 
hyphemia.  The  exudate  is  often  deposited  on  the 
posterior  surface  of  the  cornea  and  the  anterior  surface 
of  the  lens'  capsule,  which  produces  a  grayish  appear- 
ance to  the  pupillary  area.  It  sometimes  undergoes  a 
fibrinous  change,  and  the  pupillary  area  is  occluded  by 
an  apparent  membranous  formation. 

In  types  of  a  mild,  slow,  chronic  nature,  and  more 
particularly  when  the  uveal  tract  is  involved,  the 
exudate  may  be  seen  by  the  aid  of  a  strong  lens  de- 
posited, as  pin-point  dots  or  larger,  on  the  posterior 
layer,  even  when,  to  the  unaided  eye,  it  may  appear 
clear.  This  precipitates  to  the  bottom  of  the  anterior 
chamber  and  forms  a  pyramid  mass.    That  thrown  out 

8 


114  OPHTHALMOLOGY  FOR  VETERINARIANS 

from  the  posterior  pupillary  border  assists  in  cementing 
the  border  of  the  pupil  to  the  anterior  capsule  of  the 
lens,  either  partially  or  completely.  These  adhesions 
are  called  posterior  synechiae.  When  the  iris  is  com- 
pletely adherent  it  is  known  as  seclusion  of  the  pupil; 
when  this  occurs,  together  with  the  formation  of  a  mem- 
brane over  the  pupillary  area,  it  is  called  occlusion  of  the 
pupil.  When  this  takes  place  the  eye  becomes  bUnd. 
Occluded  pupil  has  frequently  been  found  in  the  horse 
as  a  sequel  of  iritis. 

An  iritis  and  a  cycHtis — iridocyclitis — often  occur  at 
the  same  time;  however,  an  inflammation  of  one  or  the 
other  of  these  bodies  may  be  more  pronounced. 

CycHtis  is  nearly  always  accompanied  by  tenderness 
over  the  ciliary  region,  and  the  congestion  is  more 
marked  over  this  locahty.  According  to  Law,  "it  occurs 
in  domestic  animals,  as  described  by  Moller,  but  he  fails 
to  furnish  instances  of  its  diagnosis  during  Hfe,  and  it  is 
not  likely  to  be  recognized  in  living  animals.  Besides  the 
usual  signs  of  iritis,  there  is  extreme  tenderness  on 
pressure  around  the  anterior  border  of  the  sclera — it 
is  quite  Hkely  to  be  complicated  by  suppuration  and  to 
go  on  to  panophthalmitis." 

Symptoms  of  Iritis.— Iriih  is  accompanied  by  pain, 
redness  of  the  conjunctiva,  small  pupil,  which  reacts 
very  sluggishly  or  not  at  all,  discoloration  of  the  iris, 
and  the  formation  of  synechise,  which  are  more  notice- 
able when  a  mydriatic  is  used.     The  tension  is  normal 


DISEASES  OF  THE  IRIS  AND  CILIARY  BODY       115 

unless  secondary  glaucoma  (see  Glaucoma)  arises. 
Although  pain  is  a  symptom  of  iritis,  it  is  not  present  in 
^all  cases,  and  the  presence  of  iritis  in  some  cases  can 
only  be  determined  by  the  use  of  the  ophthalmoscope, 
when,  after  the  use  of  a  mydriatic,  small  pigment  spots 
may  be  seen  upon  the  capsule  of  the  lens,  near  the 
pupillary  margin,  at  the  point  where  the  iris  has  be- 
come agglutinated. 

In  the  severe  types  the  pain  is  almost  unbearable, 
more  intense  at  night,  and  it  often  radiates  to  the  back 
of  the  head.  The  conjunctival  injection  is  also  very 
great,  and  if  one  is  not  on  his  guard  he  may  mistake  it  for 
a  conjunctivitis  by  ^^snap  diagnosis."  The  course  may 
be  from  one  to  several  weeks.  It  frequently  clears  up, 
but  may  recur  in  the  same  or  fellow  eye. 

Secondary  iritis  and  cyclitis  is  the  result  of  disease  of 
the  neighboring  structures  or  injury.  The  injuries  re- 
ceived by  penetrating  bodies  in  this  region  are  the  most 
apprehensive,  more  particularly  if  the  penetrating  agent 
is  not  sterile.  Wounds  of  the  ciHary  region  by  infected 
bodies  produce  terrific  reaction,  as  a  rule  often  fol- 
lowed by  loss  of  vision  and  suppuration  of  the  uveal 
tract. 

One  of  the  gravest  consequences  of  this  "condition  is 
sympathetic  involvement  of  the  other  eye— sympathetic 
ophthalmia— manifest  at  first  by  irritation,  and  later 
by  inflammation  of  the  iridociliary  region,  and  eventu- 
ally loss  of  that  eye  also.    So  that  it  behooves  us  to  ex- 


Ii6  OPHTHALMOLOGY  FOR  VETERINARIANS 

ercise  the  utmost  caution,  judgment,  and  care  in  our 
treatment  of  the  primary  cause. 

Just  how  sympathetic  inflammation  is  brought  about 
no  one  seems  to  know  definitely,  but  it  is  presumed  to  be 
effected  through  the  l3anphatic  vessels  or  the  circulatory 
system.  Many  a  person  has  become  blind  in  both  eyes, 
which  might  have  been  otherwise  had  the  injured  eye 
been  sacrificed  in  due  season. 

Whether  the  object  remains  in  the  eye  or  not,  or 
whether  this  region  has  been  simply  pierced  by  a  dirty 
instrument,  the  result  is  the  same  as  a  rule.  No  longer 
than  six  days  should  elapse  before  removing  the  offend- 
ing eye,  otherwise  the  fellow  eye  may  become  affected. 

The  iridociliary  region  is  involved  in  all  cases  of  recur- 
rent ophthalmia  of  animals,  and  it  is  not  uncommon  to 
see  the  fellow  eye  follow  in  its  wake;  but,  until  we  know 
more  definitely  what  the  exact  cause  is  of  recurrent 
ophthalmia,  we  are  at  sea  as  to  the  best  method  to 
pursue  in  preventing  sympathetic  involvement,  as  the 
cause  in  the  second  eye  may  be  the  same  as  in  the  first, 
and  not  sympathetic,  as  we  understand  sympathetic 
ophthalmia. 

Treatment  of  Iritis  and  Cyclitis. — The  treatment  is 
constitutional  and  local.  The  cause  should  be  sought 
and  that  treated.  Influenza,  tuberculosis,  rheumatism, 
and  other  forms  of  infectious  diseases  are  often  the 
cause,  and  appropriate  treatment  is  cafled  for.  Keep 
the  animal  quiet,  in  a  dark  stall,  where  it  may  be  free 


DISEASES  OF  THE  IRIS  AND  CILIARY  BODY       117 

from  the  irritating  effects  of  light,  dust,  dampness,  etc. 
Open  the  bowels  freely  and  keep  them  open,  to  reheve 
it  from  the  absorption  of  toxins.  See  that  the  animal 
is  kept  under  the  best  hygienic  conditions.  In  debili- 
tated subjects,  tone  up  the  system  by  the  administration 
of  suitable  tonics. 

Local  treatment  consists  in  preventing  the  formation 
of  synechiae,  relieving  pain,  rest  of  the  accommodation, 
depletion,  absorption  of  inflammatory  products,  etc. 

Atropin  in  solution  is  one  of  our  best  remedies  in 
iritis.  It  paralyzes  the  accommodation,  lessens  the 
congestion,  dilates  the  pupil,  thereby  preventing  the 
formation  of  adhesions  of  the  pupiflary  margin,  and 
assists  in  reheving  pain.  In  man  it  is  used  in  i  per  cent, 
solution,  but  the  solution  must  be  graduated  in  strength 
according  to  the  size  and  weight  of  the  animal.  The 
frequency  of  the  application  will  depend  largely  upon 
the  case.    Usually  three  times  a  day  is  sufficient . 

Dionin  is  one  of  the  newer  remedies,  and,  in  conjunc- 
tion with  atropin,  one  of  the  best.  It  reHeves  pain  and 
promotes  activity  of  the  lymphatic  circulation.  It 
acts  better  following  the  application  of  moist  heat. 

Heat,  properly  applied,  is  almost  indispensable.  A 
cloth  or  wad  of  absorbent  cotton  may  be  wrung  out  of 
boiling  water,  as  dry  as  possible,  and,  when  it  can  be 
borne,  placed  over  the  closed  lids.  This  should  be 
repeated  every  minute  for  six  or  eight  times  every  hour. 
The  eye  should  never  be  poulticed. 


Ii8  OPHTHALMOLOGY  FOR  VETERINARIANS 

In  cases  of  iridocyclitis,  when  the  inflammation  of  the 
ciliary  body  is  more  pronounced,  and  in  cyclitis  pure  and 
simple,  atropin  should  be  used  with  caution,  as  in  many 
cases  it  is  not  well  borne;  besides,  when  this  agent  is 
used,  the  tension  should  be  closely  watched.  Should 
any  increase  of  tension  occur  the  atropin  should  be 
immediately  stopped  and  a  myotic  employed. 

In  severe  cases  of  inflammation  and  congestion 
several  leeches  may  be  applied  over  the  region  of  the 
temple.  They  assist  greatly  in  reducing  the  inflamma- 
tory symptoms. 

Operative  measures  should  not  be  employed  during  the 
active  stage  of  inflammation  as  a  rule.  Iridectomy 
may  be  done  when  the  tension  becomes  increased,  and  it 
cannot  be  reduced  by  less  radical  means.  When  the 
pupil  becomes  secluded  or  occluded,  iridectomy  aids  in 
re-estabHshing  the  natural  drainage,  and  prevents,  in  a 
degree,  subsequent  attacks. 

When  tension  develops,  a  paracentesis  may  be  per- 
formed. It  allows  the  escape  of  the  aqueous,  together 
with  inflammatory  debris,  and  assists  in  reducing  the 
tension. 

Enucleation  should  only  be  considered  in  infected 
traumatic  cases  when  the  fellow  eye  is  in  danger  of 
sympathetic  inflammation,  and  in  cases  accompanied  or 
followed  by  suppuration  of  the  internal  structures,  or 
when  panophthalmitis  exists,  and  the  animal's  Hfe  is 


DISEASES  OF  THE  IRIS  AND   CILIARY  BODY      1 19 

endangered  by  extension  of  the  septic  elements  to  the 
meninges. 

Cysts  and  Tumors  of  the  Iris.— Cysts  of  the  iris  are 
rare,  though  they  sometimes  appear  in  the  stroma  of  the 
iris  as  the  result  of  injury.  They  are  usually  very 
gradual  in  their  development.  Meyer  (in  Law's  "Veter- 
inary Medicine")  speaks  of  these  lesions  in  horses, 
"  but  they  are  very  difhcult  to  diagnose  even  with  the  aid 


Yig,  25.— Photograph  of  carcinoma  ot  the  orbit  of  a  dog.  (Veter- 
inary Record,  vol.  xvii,  p.  694,  "  Proceedings  of  the  Central  Veter- 
inary Medical  Society.") 

of  the  ophthahnoscope.  The  very  manifest  bulging  at 
the  part  may  be  due  to  excess  of  pigment,  especially  in 
the  corpora  nigra,  and  an  exploratory  puncture  would 
only  be  warranted  when  the  protrusion  becomes  excessive 
and  injurious.  One  such  puncture  by  Eversbusch  led 
to  infection  and  loss  of  the  eye."  In  this  instance  prob- 
ably the  puncture  was  not  made  under  the  strictest 
aseptic  precautions.    The  treatment  of  cyst  of  the  iris 


I20  OPHTHALMOLOGY  FOR  VETERINARIANS 

is  incision  of  the  cyst  at  the  corneal  margin  with  a 
proper  knife-needle.  Of  course,  the  same  aseptic 
precautions  must  be  observed  as  in  all  operative  pro- 
cedures. 

Tuberculosis  of  the  Iris. — This  has  occurred  as  a  result 
of  general  infection  in  the  smaller  animals,  and  as  a 


Fig.  26. — Photograph  of  carcinoma  of  the  orbit  of  a  cat.  (Veter- 
inary Record,  vol.  xvii,  p.  694,  "  Proceedings  of  the  Central  Veter- 
inary Medical  Society.") 

spontaneous  localization  of  disease  in  cattle.  In  Hess' 
case  ''the  left  eye  was  shrunken  to  half  the  size  of  the 
sound  eye,  and  the  small  caseated  nodules  were  present 
in  both  iris  and  chorioid."  There  are  usually  co-existing 
tubercles  in  other  organs,  and  these,  together  with  the 
nodular  swellings  of  the  iris,  may  assist  in  the  diagnosis. 


DISEASES  OF  THE  IRIS  AND  CILIARY  BODY       I2i 

''Animals  in  which  the  eyes  have  been  experimented  on 
by  inoculation  die  of  general  tuberculosis  due  to  infec- 
tion starting  from  the  eye"  (Duane). 

Tumors  of  the  iris  and  ciliary  body  are  benign  and 
malignant.  The  corpora  nigra,  which  is  normal,  of 
course,  is  an  example  of  the  so-called  melanomata  which 


Fig.  27.-Sarcoma  of  the  left  orbit.     (Dr.  Geo.  H.  Robberts'  case.) 


occur  in  the  iris.  It  springs  from  the  pigment  layer  at 
the  margin  of  the  pupil.  Another  form  is  an  excess  of 
pigment  springing  from  the  iris  stroma  and  projecting 
into  the  anterior  chamber.  They  develop  to  a  certain 
size  and  may  remain  stationary.  Portions  of  the  pig- 
ment mass  may  become  loose  from  the  main  body  and 
fall  into  the  anterior  chamber.     They  are  benign  in 


122  OPHTHALMOLOGY  FOR  VETERINARIANS 

character,  but  must  produce  more  or  less  irritation  of  the 
iris  in  its  movements  of  contraction  and  dilatation. 

Sarcoma  sometimes  makes  its  appearance  inde- 
pendently in  the  ciHary  body  and  iris,  but  is  more  often 
extended  to  these  portions  from  primary  affection  of  the 


Fig.  28. — ^The  contents  of  the  left  orbit  in  Fig.  24,  cut  in  the  center 
from  above  downward:  a,  the  eyeball;  6,  the  retractor  muscle;  c,  the 
normal  tissue;  d,  the  tumor  mass. 


chorioid  or  the  anterior  portion  of  the  eye.  It  is  pig- 
mented (melanotic),  and  when  it  is  confined  to  the 
ciHary  body  it  cannot  be  seen  or  discovered  until  it  has 
reached  a  sufhcient  size,  as  the  ciliary  region  is  always 
difficult  to  see  with  the  ophthalmoscope  because  it  is 
located  so  far  anteriorly.     Its  location  may  be  deter- 


DISEASES  OF  THE  IRIS  AND  CILIARY  BODY       123 

mined  with  the  transilluminator.    This  tumor  is  sooner 
or  later  destructive  to  the  eyeball  and  possibly  to  life. 


Fig.  29.— Melanosarcoma  of  the  human  eye.  Prepared  by  the 
author.  Notice  the  detachment  and  folding  of  the  retina  and  the 
arched  condition  of  the  posterior  portion  of  the  lens  which  is  pushed  for- 
ward to  the  cornea,  practically  gluing  the  iris  to  it.  This  is  due  to  the 
extreme  intra-ocular  tension. 

The  only  thing  to  do  is  to  enucleate  the  eye  as  soon  as  it 
is  discovered. 


CHAPTER  X 

DISEASES  OF  THE  RETINA  AND  CHORIOID 

Diseases  of  these  coats  and  also  of  the  optic  nerve 
are  diagnosed  by  the  use  of  the  ophthahnoscope.  This 
instrument  is  devised  for  throwing  reflected  light  into 
the  eye  from  a  tilting  mirror  in  front  of  a  series  of  spheric 
lenses;  a  hole  is  in  the  center  of  the  mirror,  and  the 
small  lenses  are  protected  by  a  circular  revolving  disk. 
Two  methods  of  examination  are  used:  The  direct 
method,  by  which  the  physician  looks  directly  through 
the  hole  in  the  mirror,  the  same  being  close  to  the 
animal's  eye.  The  light  (a  candle  is  sufficient)  is  placed 
to  the  right  of  the  animal's  head  if  the  right  eye  is  to 
be  examined,  the  ophthalmoscope  being  held  in  the  right 
hand,  and  the  examiner  uses  his  right  eye.  In  examining 
the  left  eye,  hold  the  instrument  in  the  left  hand,  and 
look  through  the  hole  in  the  mirror  with  the  left  eye. 
The-'  light  should  be  on  the  left  side  of  the  animal's 
head.  When  examining  either  eye  the  mirror  is  brought 
close  to  the  eye  of  the  animal,  and  so  tilted  as  to  produce 
a  red  reflex,  when  the  fundus  will  be  illuminated.  If 
the  vessels  are  seen,  but  are  indistinct,  the  disk  may  be 
turned  so  as  to  bring  out  the  vessels  sharply  by  either 

124 


DISEASES  OF  THE  RETINA  AND   CHORIOID        125 

a  plus  or  minus  spheric  lens.  The  numbers  of  the  plus 
lenses  are  usually  white,  while  those  of  the  minus  lenses 
are   red.    The  examiner's  eyes  should  both  be  open, 


Fig.  30.— Loring's  ophthalmoscope,  with  tilting  mirror,  complete  disk 
of  lenses  from  — i  to  -8  and  o  to  +7,  and  supplemental  quadrant  con- 
taining ±0.5  and  ±16  D.  This  affords  66  glasses  or  combinations  from 
+  23  to— 24D. 

and  the  accommodation  relaxed,  as  in  viewing  objects 
through  the  microscope.  The  indirect  examination  is 
made  at  a  greater  distance  from  the  animal's  eye,  and 


126  OPHTHALMOLOGY  FOR  VETERINARIANS 

with  the  addition  of  a  spheric  lens  of  about  +i6 
diopters.  In  using  this  method  the  disk  should  be 
turned  so  that  a  +3  D.  lens  shows  behind  the  hole  in 
the  mirror.  Support  the  16  D.  lens  with  the  thumb  and 
index-finger  of  the  right  hand  (for  the  left  eye,  and  with 
those  of  the  left  hand  for  the  right  eye) ,  and  allow  the 
Httle  finger  to  rest  upon  the  face  near  the  eye,  so  as  to 
guide  the  distance  between  the  eye  and  the  lens.  The 
examiner  will  hold  the  ophthalmoscope  close  to  his  own 
eye,  and  pass  the  reflected  light  through  the  16  D.  lens 
near  the  animal's  eye.  This  method  gives  a  greater 
field,  but  a  reduced  image,  and  usually  brings  out  the 
retinal  vessels  and  optic  disk  distinctly,  even  in  cases 
of  a  high  myopia. 

It  will  be  well  for  the  veterinary  student  to  use  the 
ophthalmoscope  as  much  as  possible  in  the  examination 
of  the  eyes  of  various  animals,  and  become  acquainted 
with  normal  fundi.  This  is  the  only  possible  way  to  be 
able  to  distinguish  a  normal  from  a  diseased  fundus. 
Examine  the  human  eye  also,  and  study  the  difference 
in  the  structure  of  the  coats  and  the  arrangement  of  the 
vessels  from  those  of  dumb  animals'  eyes.  (See  Frontis- 
piece.) 

Normal  fundi  of  animals  of  a  kind  are  the  same, 
though  they  may  differ  in  degree  of  shade  or  color 
according  to  the  amount  of  pigment.  Anomalous  con- 
ditions (such  as  coloboma  of  the  chorioid  or  retina)  may 
be  mistaken  for  a  pathologic  change,  but  experience  in 


DISEASES  OF  THE  RETINA  AND   CHORIOID        127 

examination  will  teach  one  the  difference.  The  tape  turn 
lucidum  may  also  be  mistaken  for  a  pathologic  lesion. 
The  brilliancy  and  varied  coloring  of  this  portion  of  the 
fundus  is  most  interesting.  A  fowl's  fundus  distinctly 
differs  from  a  quadruped's.  There  is  a  projection  into 
the  vitreous,  known  as  the  ^'pecten,"  said  by  some 
authors  to  be  a  projection  of  the  chorioid,  and  by  others 
to  be  a  portion  of  the  retinal  circulation.  It  appears  on 
cross-section  of  the  eye  to  project  from  the  optic  nerve. 

The  retina,  although  histologically  divided  into  ten 
layers,  may  properly  be  divided  into  tissues  of  two 
kinds— a  nervous  and  a  supporting  tissue.  It  is  said  to 
be  transparent,  which  is  quite  evident  in  fundi  with 
little  or  no  pigment  when  the  outlines  of  the  vessels  of  the 
chorioid  can  be  seen  through  it.  Its  system  of  blood- 
vessels is  particularly  its  own,  as  they  do  not  anastomose 
with  themselves  or  other  systems  of  vessels  except  at  the 
papilla,  where  there  is  a  minute  connection  between  the 
retinal  and  ciHary  vessels. 

The  retina  is  subject  to  anemia,  edema,  hyperemia, 
hemorrhages,  detachment,  inflammation,  and  atrophy. 

Anemia  occurs  with  general  anemia  and  follows  severe 
hemorrhages  from  other  portions  of  the  body.  It  also 
occurs  in  compression  and  embolism  of  the  central 
artery.  There  is  a  reduction  in  the  cahber  of  the  vessels 
and  the  retina  is  generally  pale. 

Edema  is  the  result  of  traumatism  and  disease,  and  is 
due  to  effusion  in  the  retinal  tissues.     It  presents  a 


128  OPHTHALMOLOGY  FOR  VETERINARIANS 

cloudy  appearance,  which  may  sooner  or  later  clear 
away,  leaving  retinal  change.  It  usually  causes  a 
reduction  of  sight. 

Hyperemia  accompanies  inflammatory  diseases  of  the 
retina  and  optic  nerve,  and,  in  man,  a  simple  hyperemia 
is  often  due  to  eye-strain  and  excessive  Hght. 

Hemorrhages  usually  follow  injuries,  diseases  of  the 
blood-vessels,  retina  and  chorioid,  and  sometimes  take 
place  when  inflammation  is  not  present.  They  occur 
along  the  course  of  a  vessel  and  are  irregular  in  outline. 
When  they  occur  in  the  macular  region  the  animal  is 
bhnd  in  the  central  field.  Sometimes  large  hemorrhages 
between  the  hyaloid  membrane  and  the  retina  occur, 
which  precipitate  and  form  a  peculiar  shape  (subhya- 
loid  hemorrhage).  When  the  blood  is  absorbed,  which 
usually  takes  a  long  time,  pigmented  spots  or  atrophic 
white  spots  remain  over  the  site. 

Detachment  is  often  due  to  injuries  and  diseases, 
which  cause  a  fluid  vitreous  and  loss  of  support  of  the 
retinal  tissue,  or  to  an  accumulation  of  fluid  between  the 
retina  and  chorioid  when  the  former  is  pushed  forward. 
The  detachment  may  be  confined  to  a  localized  area, 
as  it  is  at  first,  and  may  then  become  total.  The  visual 
fields  are  largely  disturbed  in  partial  detachment,  and 
in  total  detachment  complete  bhndness  will  follow. 

Retinitis,  or  inflammation  of  the  retina,  is  varied  in 
appearance  and  cause.  It  is  characterized  by  hyperemia 
and  edema,  indistinct  outlines  of  the  papilla,  tortuous 


DISEASES  OF  THE  RETINA  AND   CHORIOID         129 

veins,  and,  in  many  cases,  numerous  hemorrhages. 
White  spots  appear  scattered  about  the  fundus,  due  to 
the  presence  of  exudates.  These  exudates  often  pass 
into  the  vitreous,  causing  opacities  in  this  substance. 
The  vision  is  reduced  according  to  the  site  and  degree 
of  the  inflammation,  which  is  general,  though  it  may  be 
localized. 

The  appearance  by  ophthalmoscopic  examination 
often  depends  upon  the  cause,  though  in  many  cases 
the  cause  is  not  easily  found.  Among  the  various  causes 
are  Bright's  disease,  diabetes,  syphiHs,  diseases  of  the 
vascular  system,  and  diseases  of  the  blood. 

The  characteristic  early  appearance  in  Bright's 
disease  is  a  radiation  of  white  spots  about  the  macula 
with  occasional  hemorrhages,  and  larger  exudates  in 
various  portions  of  the  retina,  together  with  other  lesions 
above  described.  This  form  of  retinitis  frequently^ 
occurs  in  the  bitch  during  the  stage  of  pregnancy. 

The  only  way  to  determine  the  cause  of  retinitis  is 
to  give  the  animal  a  thorough  physical  examination,  in- 
cluding a  chemic  and  microscopic  examination  of  the 
urine  and  blood. 

Atrophy  of  the  retina  often  occurs  as  a  result  of  a  long 
period  of  inflammation,  or  the  reduction  of  its  nutrition 

There  is  one  particular  condition  which  is  not  infrequent  and  should 
not  be  mistaken  as  pathologic;  this  is  a  series  of  medullated  fibers  which 
appear  like  a  white  flame  extending  from  the  optic  nerve  upward  and 
downward,  or  in  one  direction  only.  In  such  a  case  the  general  symptoms 
of  retinitis  are  absent. 
9 


130  OPHTHALMOLOGY  FOR  VETERINARIANS 

from  embolism  or  thrombosis  of  its  vessels.  The  latter 
become  very  small  or  obliterated,  though  the  remaining 
portion  of  the  retina  may  appear  normal. 

Rupture  of  the  retina  is  the  result  of  injuries,  princi- 
pally contusions  of  the  eyeball.  "Cases  of  isolated  lacera- 
tion of  the  retina  are  extremely  rare.  The  retina  is  much 
harder  to  tear  than  the  chorioid,  since  in  rupture  of  the 
latter  the  retina  is  generally  found  to  be  uninjured" 
(Duane). 

Glioma. — Because  of  the  structure  of  the  retinal  tis- 
sue glioma  is  the  only  growth  the  retina  is  subject  to. 
For  a  long  time  it  has  been  known  as  "amaurotic  cat's 
eye,"  from  the  fact  that  the  eye  is  blind,  and  the  fundus 
reflex  looks  like  that  from  the  tapetum  of  the  retina  of 
the  cat's  eye  in  the  dark.  A  glioma  is  a  very  malignant 
tumor  and  occurs  in  the  young.  If  not  early  removed,  it 
soon  extends  to  the  optic  nerve  and  brain  and  results 
fatally.  Besides  extending  backward,  it  grows  forward 
and  laterally  into  the  tissues  of  the  orbit.  The  globe  is 
much  enlarged  and  ugly  ulcerations  may  take  place. 
It  may  attack  one  or  both  eyes.  It  is  one  of  the  most 
malignant  and  fatal  diseases  of  the  eye  with  which  we 
have  to  deal. 

Diseases  of  the  Chorioid 

Because  of  the  close  connection  with  the  retina 
these  two  coats  are  nearly  always  affected  when  one  or 
the  other  is  first  inflamed.    This  is  known  as  a  retino- 


DISEASES  OF  THE  CHORIOID  131 

chorioiditis;  however,  diseases  of  these  eoats  do  appear 
to  exist  independently,  and  when  the  chorioid  alone  is 
inflamed  it  is  called  chorioiditis.  The  distinction  is  made 
by  the  retinal  vessels,  without  a  break,  passing  over  the 
chorioidal  lesion. 

The  chorioid  is  a  portion  of  the  uveal  tract  extending 
forward  and  including  the  ciliary  body  and  iris,  and 
these  bodies  are  often  inflamed  in  conjunction  with  the 
chorioid,  when  it  is  known  as  iridochorioiditis.  These 
are  the  parts  first  affected  in  recurrent  ophthalmia. 

The  chorioid  is  a  vascular  and  pigmentary  coat,  with 
supporting  connective  tissue,  and  is  subject  to  simple 
and  inflammatory  affections.  It  rests  upon  the  white 
sclera,  and  for  this  reason  rupture  of  the  coat  can  be 
easily  seen,  as  can  the  crescentic  rupture  near  the 
papifla  in  cases  of  high  myopia. 

The  early  stages  of  chorioiditis  are  manifest  by  various 
spots  of  a  yellowish-white  color  due  to  exudates,  when 
the  retinal  vessels  may  be  seen  passing  over  them. 
Later,  by  a  proliferation  of  pigment,  these  spots  appear 
black,  particularly  about  the  borders.  There  is  always 
a  disturbance  of  vision,  with  a  sensation  of  flashes  of 
light,  with  marked  scotomata.  The  causes  are  syphihs, 
scrofula,  tuberculosis,  and  diseases  of  the  blood.  In 
cases  of  high  myopia  the  chorioid  suffers  many  changes 
by  reason  of  severe  stretching. 

According  to  the  location  and  distribution  of  the  spots 
or  lesions,  chorioiditis  is  known  as  central,  disseminated, 


132  OPHTHALMOLOGY  FOR  VETERINARIANS 

and  diffuse.  If  the  macula  does  not  become  affected, 
central  vision  remains  good.  There  is  little  hope  of  re- 
storing the  chorioid  to  its  normal  conditions,  as  atrophy 
of  the  affected  areas  usually  follow. 

Purulent  chorioiditis  is  the  result  of  infected  wounds, 
ulceration  of  the  cornea,  and  metastasis  in  cases  of 
pyemia  and  septicemia.  The  whole  uveal  tract  is  usu- 
ally involved.  It  may  undergo  absorption  when  the 
globe  becomes  shrunken.  Panophthalmitis  is  a  condi- 
tion in  which  the  globe  ruptures  in  its  orbital  portion, 
affecting  the  orbital  tissues;  or  purulent  inflammation 
may  originate  in  the  orbit  and  perforate  the  coats  of 
the  eye. 

In  all  the  forms  of  optic  neuritis,  retinitis,  and  chori- 
oiditis, except  the  purulent  type  and  those  associated 
with  iritis,  there  is  no  pain  and  no  external  evidence  of 
the  disease.  The  diseases  of  the  retina  and  chorioid  are 
spoken  of  by  some  as  ''internal  ophthalmia,"  but  this 
term  is  indefinite,  except  to  indicate  an  inflammation  of 
the  internal  structures  of  the  eye. 


CHAPTER  XI 

DISEASES  OF  THE  OPTIC  NERVE 

The  optic  nerve  is  subject  to  inflammation  at  any 
point  along  its  course.  When  it  occurs  in  the  anterior 
portion  it  may  gradually  ascend  along  the  trunk,  and 
when  the  initial  trouble  is  along  the  trunk  it  may  descend 
to  the  optic  disk,  and  will  be  followed  by  atrophy  in  many 
cases.  When  the  disk  is  inflamed  the  retina  is  nearly  al- 
ways involved,  when  it  is  known  as  neuroretinitis.  The 
causes  are  traumatism,  inflammation  of  adjacent  struc- 
tures, tumors,  hemorrhages,  and  diseases  of  the  central 
nervous  system.  A  portion  of  the  fibers  only  may  be 
affected,  when  vision  will  be  partly  retained,  but  if  ah 
the  fibers  are  involved  and  atrophy  follows,  vision  wifl 
be  entirely  lost.  When  one  eye  only  is  affected  the 
cause  Hes  anterior  to  the  optic  chiasm. 

Papillitis  is  an  inflammation  of  the  optic  nerve  head 
or  papilla.  It  is  usually  bilateral,  and  is  due  either  to 
pressure  upon  the  nerves  or  tracts  or  to  effusion  within 
the  sheaths  or  fibers.  The  papillae  are  edematous  and 
swollen,  larger  than  normal,  and  may  be  reddish,  gray, 
pale,  or  even  white,  and  the  outlines  are  very  indistinct. 
The  arteries  are  small,  while  the  veins  are  large  and 


133 


134  OPHTHALMOLOGY  FOR  VETERINARIANS 

tortuous.  The  disk  appears  ' 'choked/'  and  the  tissues 
have  a  striated  appearance  from  the  center  outward, 
extending  into  the  retina.  Vision  may  be  normal  in 
some  cases,  though  a  marked  decrease  in  the  fields  and 
acuity  of  vision  is  the  rule,  and  sudden  blindness  some- 
times occurs.    The  prognosis  is  always  grave. 

Retrobulbar  neuritis  is  inflammation  of  the  nerve 
within  the  orbit,  posterior  to  the  globe.  It  is  often  caused 
by  influenza  and  catarrhal  disturbances  of  the  nasal 
passages,  involving  the  sinuses  directly  adjacent  to  the 
orbital  tissues.  It  may  occur  in  one  or  both  nerves. 
Total  blindness  may  follow  an  acute  attack,  caused  by 
severe  inflammation  of  the  orbital  tissues,  though 
in  the  majority  of  cases  only  a  varying  decrease  in  the 
visual  acuity  is  the  result.  The  fundus  is  normal  in 
appearance,  though  atrophy  of  the  nerve-fibers  may  take 
place  and  descend  to  the  papilla,  when  it  will  gradually 
become  white.  The  prognosis  is  usually  good  if  the 
cause  is  removed  and  the  nerve-fibers  toned  by  proper 
medication. 

Toxic  amblyopia  is  due  to  poisons  within  the  system. 
In  man,  alcohol  and  tobacco  are  the  principal  causes, 
though  lead,  arsenic,  and  various  other  chemic  poisons 
may  be  the  cause.  Quinin  in  large  doses  has  produced  it. 
^'Anatomic  investigations  in  quinin-poisoning,  produced 
experimentally  in  dogs,  shows  during  the  very  first 
days  a  destruction  of  the  ganglion  cells  of  the  retina, 
these  being  primarily  attacked  by  the  poison"  (Duane). 


DISEASES  OF  THE  OPTIC  NERVE  135 

It  is  manifest  by  a  gradual  or  rapid  reduction  in  sight. 
The  central  field  is  the  one  involved,  and  from  this  fact 
it  is  possible  that  the  poison  may  attack  the  nerve  ele- 
ments of  the  macula  first  and  then  recede  to  the  optic 
nerves.  Colors  are  not  easily  distinguished,  especially 
red  and  green. 

The  treatment  in  such  cases  is  to  remove  the  cause, 
keep  the  bowels  open,  and  tone  up  the  nerve-fibers  by  the 
use  of  strychnin. 

Atrophy  of  the  optic  nerve  may  be  simple  or  inflam- 
matory. In  the  former  the  nerve  head  becomes  gradually 
white,  without  symptoms  of  inflammation  accompanying 
it.  The  sight  is  gradually  reduced  until  there  is  com- 
plete blindness.  The  principal  causes  are  affections  of 
the  brain  and  tabes  dorsahs  (sclerosis  of  the  posterior 
columns  of  the  spinal  cord).  The  author  once  saw  a 
case  of  this  kind  in  a  cat  in  which  both  optic  nerves 
were  entirely  atrophied,  with  sight  and  locomotion 
abolished. 

Inflammatory  atrophy  is  the  result  of  optic  neuritis, 
with  symptoms  like  those  described  under  Papillitis. 
After  the  swelling  of  the  nerve  head  subsides  the  out- 
line becomes  more  distinct  and  smaller  in  size,  and  the 
large  and  tortuous  vessels  become  contracted.  The 
papilla  has  a  white  appearance,  sharply  defined.  The 
prognosis  is  always  unfavorable. 

The  treatment  should  be  aimed  at  the  cause,  together 
with  tonics  and  alteratives  for  the  nerve  lesion. . 


136  OPHTHALMOLOGY  FOR  VETERINARIANS 

It  is  of  the  utmost  importance,  in  passing  one's  judg- 
ment upon  the  soundness  of  an  animal,  that  the  optic 
nerves  be  examined — in  fact,  the  whole  fundus  of  the 
eye;  for,  however  sound  an  animal  may  be  otherwise, 
if  the  fundus  is  or  has  been  diseased,  it  materially 
lessens  the  animal's  value.  In  order  to  determine  a 
pathologic  condition  one  must  become  famihar  with  the 
normal  fundus,  and  advantage  should  be  taken  of  every 
opportunity  to  learn  its  details. 


CHAPTER  XII 

DISEASES  OF  THE  LENS 

Cataract. — A  cataract  is  an  opacity  of  the  crystalline 
lens,  its  capsule,  or  both.  Animals  are  as  subject  to 
cataract  as  man.  The  horse,  dog,  and  cat  are  frequently 
seen  with  cataractous  lenses. 

Normally,  the  lens  is  transparent,  but  as  one  advances 
in  life  it  becomes  less  transparent  and  assumes  a  hazy 
appearance  when  viewed  obliquely.  This  is  due  to  an 
increase  in  its  density.  Under  this  condition  the  vision  is 
probably  as  good  as  in  early  life,  when  the  lens  is  much 
softer,  though  often  in  man  the  density  becomes  so  great 
that  near-sightedness  is  developed  by  virtue  of  changes 
in  its  refraction.  In  such  instances  elderly  people  read 
print  without  the  aid  of  glasses,  and  they  think,  as  is 
often  remarked,  they  have  their  ''second  sight."  Such 
cases,  however,  are  apt  to  be  followed  by  cataractous 
changes. 

Classification. — Cataracts  are  classified,  according  to 
age,  density,  course,  etc.,  as  congenital,  senile,  soft, 
hard,  incipient,  mature,  primary,  secondary,  capsular, 
lenticular,  stationary,  progressive,  traumatic,  etc. 

When  an  animal  is  born  with  cataractous  lenses  it  is 

137 


138  OPHTHALMOLOGY  FOR  VETERINARIANS 

the  congenital  type,  and  is  due  to  faulty  nutrition.  A 
senile  cataract  occurs  late  in  life  when  the  lens  becomes 
sclerosed,  and  is  due  also  to  faulty  nutrition  or  to  the 
absorption  of  toxins  from  the  circulation;  and  here  a 
toxic  type  might  be  mentioned,  produced  either  by  auto- 
intoxication or  the  ingestion  of  toxic  agents,  such  as  the 
ergot  of  rye,  for  example.  Soft  cataracts  occur  in  the 
young  and  hard  cataracts  in  aged  subjects.  An  incipient 
cataract  is  one  in  its  initial  stage,  before  the  vision  has 
become  impaired,  while  a  mature  cataract  is  a  lens  which 
has  undergone  complete  change.  This  is  also  known  as 
a  ''ripe"  cataract,  and  is  ready  for  extraction.  A 
primary  cataract  is  one  that  appears  without  apparent 
cause,  while  a  secondary  cataract  follows  disease  of 
other  structures  of  the  eye,  such  as  glaucoma,  etc. 
Lenticular  cataract  is  confined  to  the  lens;  it  is  also 
known  as  cortical  or  nuclear,  according  to  the  location 
of  the  opacity.  When  a  cataract  remains  in  the  same 
condition  for  a  long  period  of  time  it  is  said  to  be  sta- 
tionary. The  posterior  polar  cataract  is  classified 
under  this  head,  and  also  as  congenital  and  capsular, 
and  its  cause  differs  from  that  of  other  cataracts.  A 
progressive  cataract  is  one  that  steadily  advances  to 
maturity.  Traumatic  cataracts  are  the  result  of  either 
direct  violence  or  accident  during  operations. 

As  a  rule,  a  cataract  does  not  lessen  the  vision  unless 
it  is  centrally  located.  There  is  no  inflammation  present 
that  is  dependent  upon  a  cataract  unless  it  is  com- 


DISEASES  OF  THE  LENS  139 

plicated  with  diseases  of  other  structures.    The  size  of 
the  pupil  is  not  affected  unless  iritis  or  glaucoma  exist. 

When  a  cataract  occupies  the  pupillary  area  the  color 
of  the  pupil  changes  from  its  dense  black  to  a  bluish- 
white  or  gray  appearance. 

In  examining  the  lens  for  incipient  cataract  the  pupil 
should  be  dilated  by  the  use  of  atropin  and  illuminated 
by  oblique  Hght  or  the  transilluminator,  when  spokes  in 
the  extreme  border  of  the  lens  can  be  seen  radiating 
toward  the  center.  They  can  easily  be  seen  through  a 
strong  lens  by  the  aid  of  the  ophthalmoscope. 

A  senile  cataract  usually  begins  in  this  way,  by 
branching  or  spoke-like  opacities  radiating  from  the 
periphery. 

As  before  mentioned,  auto-intoxication  has  been 
hinted  at  as  a  cause  of  this  type  of  cataract.  The  lens 
is  a  non-vascular  body,  and  receives  its  nourishment 
from  the  ciliary  processes  through  the  circumlental 
space.  It  is  suspended  by  Zinn's  ligament,  which  not 
only  fuses  with  the  lens  capsule,  but  apparently  dips  into 
the  lens  substance  somewhat,  producing  a  sort  of 
serrated  condition  of  the  peripheral  portion.  It  is  at 
this  particular  point  that  the  cataractous  spokes  appear 
to  arise. 

A  cataract  of  the  senile  type  is  divided  into  four 
stages— viz.,  incipiency,  intumescence,  maturity,  and 
hypermaturity  or  degeneration.  Nothing  of  importance 
is  noticeable  during  the  first  stage,  unless  it  be  com- 


I40  OPHTHALMOLOGY  FOR  VETERINARL\NS 

plicated  with  pathologic  changes  in  the  chorioid  and 
retina.  The  lens  during  the  second  stage  becomes 
swollen  because  it  has  absorbed  fluid,  and  the  iris  is 
pushed  forward  in  consequence,  but  not  until  the 
striae  reach  the  pupillary  or,  rather,  central  area,  and  the 
lens  assumes  a  bluish-white  color  and  becomes  partially 
opaque,  is  vision  disturbed  to  any  great  degree. 

A  gradual  mersion  from  the  second  to  the  third  stage 
takes  place  when  the  lens  becomes  totally  opaque;  the 
excess  of  fluid  is  lost  and  it  resumes  its  normal  size. 
During  this  stage  there  is  no  fundus  reflex,  the  pupillary 
area  appears  white  and  the  vision  is  nil,  though,  if  there 
is  no  fundus  disease,  light  may  be  perceived  and  also  the 
direction  from  which  it  comes.  This  is  known  as  hght 
perception  and  projection,  which  might  be  difficult  to 
obtain  in  the  animal.  The  operation  for  cataract  (ex- 
traction) should  be  done  during  this  stage. 

The  fourth  stage  is  indicated  by  a  liquefaction  of  the 
cortical  portion  of  the  cataract  by  reason  of  fatty  de- 
generation. 

The  nucleus,  however,  retains  its  hardness,  and 
remains  so  for  years,  floating  in  the  milky-like  Hquid  of 
the  remaining  portion  of  the  lens  within  its  capsule. 
In  many  cases  the  capsule  itself  sooner  or  later  becomes 
cataractous,  and  when  this  occurs  an  operation  of  ex- 
traction is  Hable  to  be  attended  with  compHcations. 

A  secondary  or  capsular  cataract  often  occurs  after 
the   extraction   of   the   lens    if    an    extraction   is   done 


DISEASES  OF  THE  LENS  141 

without  removing  the  entire  capsule  at  the  time.  Ex- 
traction of  the  lens  in  and  with  the  capsule  is  practised 
by  many  operators,  but  with  animals  it  would  be  a 
hazardous  undertaking,  as  it  requires  much  time,  care, 
and  special  skill,  besides  there  is  greater  danger  of  losing 
much  vitreous  and  possibly  the  eye  itself. 

A  capsular  cataract  is  due  to  a  proKferation  of  cells 
.upon  its  surface  and  a  thickening  of  the  capsule,  which 
does  not  occur  until  some  time  after  extraction.  It 
eventually  diminishes  the  effect  of  the  operation.  In 
hypermature  cataracts  this  change  takes  place  in  com- 
mon with  the  degeneration  of  the  lens  substance. 

In  some  instances  a  cataract  will  clear  up  spon- 
taneously, though  when  it  becomes  complete  there  is 
less  probability  of  it  doing  so.  In  traumatic  cataract, 
when  the  lens  is  soft  and  the  capsule  is  completely 
ruptured,  so  that  the  lens  substance  escapes,  it  is  usually 
absorbed.  This  process  of  absorption  sometimes  takes 
place  very  rapidly,  even  within  forty-eight  hours  after 
the  injury.  In  traumatic  cataract  of  old  and  hard  lenses 
this  ready  absorption  does  not  take  place;  on  the  con- 
trary, the  lens  remains  cataractous,  and  often  swells  to 
such  a  degree  as  to  produce  much  increase  of  tension 
and  severe  pain,  when  immediate  extraction  is  often 
necessary. 

In  the  early  stages  of  cataract  massage  over  the 
closed  Kds  has  apparently  benefited  some  cases,  while 
in  others  it  has  seemed  to  create  an  increase  in  the 


142  OPHTHALMOLOGY  FOR  VETERINARIANS 

rapidity  of  the  cataractous  formation.  Drops  of  various 
kinds  have  been  placed  upon  the  market  which  are 
claimed  to  promote  absorption,  but,  having  been  tried 
by  eminent  men  in  the  profession,  they  have  been  found 
to  have  no  value  in  this  respect.  After  a  cataract  has 
been  formed  there  is  no  treatment  except  rehef  by  opera- 
tion. 

Luxation  of  the  Lens. — The  lens  becomes  dislocated 
by  reason  of  traumatism,  extreme  muscular  exertion, 


Cornea 
Dislocated  lens 


Cilia 


Fig.  31. — Vertical  section  of  eyeball  of  horse,  showing  dislocated  lens 
in  anterior  chamber.     Dotted  line  indicates  normal  position. 

sudden  reduction  of  tension,  extreme  increase  of  ten- 
sion, atrophy  of  the  fibers  of  the  zonule  of  Zinn,  particu- 
larly in  hypermature  cataract.  In  short,  by  stretching 
or  rupture  of  the  suspensory  ligament. 

In  cases  of  partial  luxation  the  border  of  the  lens  may 
be  tilted  backward  or  forward.  In  complete  luxation 
the  lens  may  be  forced  backward  into  the  vitreous,  and 
in  rare  instances  it  is  forced  forward  beneath  the  con- 


DISEASES  OF  THE  LENS  143 

junctiva.    In  man  it  has  been  driven  through  the  coats 
of  the  globe  into  Tenon's  capsule. 

Luxation  backward  into  the  vitreous  is  the  most 
common.  It  may  remain  there  without  causing  any 
special  reaction,  though  it  frequently  causes,  in  trau- 
matic cases,  hemorrhage  and  inflammation  of  the  inner 
coats  of  the  eye,  eventually  resulting  in  shrinking  of  the 
globe. 

In  a  dislocated  cataractous  lens  the  treatment,  in 
man,  would  be  to  allow  the  lens  to  gravitate  into  the 
anterior  chamber,  fix  it  with  a  needle,  and  extract  it 
by  the  usual  method,  by  passing  a  loop  or  wire  spoon 
beneath  it.  This  method  would  be  impracticable  in 
animals.  One  might  attempt  to  fix  the  lens  if  it  can  be 
favorably  placed  and  scoop  it  out  carefully.  An  outer 
or  inferior  section  should  be  made,  as  one  has  a  greater 
field  in  which  to  work,  and  the  wound  can  be  more 
readily  inspected  and  cleansed. 

Lenticonus.— This  is  an  anomalous  condition,  and 
has  been  found  in  the  pig  and  rabbit  by  Hess,  as  de- 
scribed by  Norris  and  Oliver.  In  each  case  the  lens 
was  without  a  nucleus  and  cone  shaped,  with  the  apex 
pointing  backward.  Although  the  anterior  portion  was 
clear  with  normal  capsule,  the  lens  substance  had  under- 
gone granular  degeneration.  Several  investigators  have 
found  this  condition  in  the  eyes  of  rabbits. 


CHAPTER  XIII 

OPERATIONS  FOR  CATARACT 

There  are  two  principal  operations  for  cataract — 
discission  and  extraction.  The  former  is  employed  only 
in  cases  of  congenital  cataract,  or  when  it  is  acquired 
in  early  life,  when  the  cataract  is  soft  and  undergoes  ab- 
sorption readily. 

Discission  of  Cataract. — The  ultimate  object  of  this 
operation  is  to  produce  absorption  of  the  lens  by  break- 
ing up  its  substance  by  the  use  of  a  small  knife-needle. 
The  eye  should  be  washed  with  an  antiseptic  solution  of 
bichlorid  of  mercury,  i  :  5000,  and  the  pupil  dilated  with 
atropin  solution  of  i  per  cent.  It  should  then  be  anes- 
thetized with  cocain  of  5  to  10  per  cent,  solution.  The 
speculum  may  be  used,  or  an  assistant  may  hold  the 
lids  apart.  The  knife-needle  is  then  passed  through  the 
cornea  near  its  margin — never  through  the  center — 
and  pushed  diagonally  through  the  lens  capsule  and  into 
the  lens  substance.  An  upward  and  downward  move- 
ment of  the  handle  causes  the  lens  to  be  cut  and  broken. 
The  knife-needle  must  be  withdrawn  in  the  direct  line 
of  its  entrance. 

If  absorption  of  the  lens  substance  does  not  readily 

144 


OPERATIONS  FOR  CATARACT         145 

occur,  this  operation  may  be  repeated;  in  fact,  several 
operations  may  be  necessary  to  produce  complete  ab- 
sorption. 

In  some  cases  following  discission  swelling  of  the 
lens  takes  place,  which  causes  pressure  upon  the  anterior 
drainage  canal  (canal  of  Schlemm),  producing  an  in- 
creased tension,  often  accompanied  with  much  pain. 
If  this  persists  after  the  use  of  ice-cold  applications  and 
rest,  it  may  be  necessary  to  make  an  incision  of  the 
cornea  at  its  margin  and  allow  the  lens  substance  to 
escape.  In  severe  cases  of  increased  tension  an  iridec- 
tomy may  be  performed.  Iritis  of  a  severe  type  may  be 
produced  by  irritation  from  floating  particles  of  the 
lens.  This  must  be  met  by  the  use  of  atropin  and  hot 
appHcations  locally,  purgatives,  rest,  and  a  dark  stall. 

Extraction  of  Cataract. — This  operation  is  adapted 
for  all  hard  cataracts,  and  for  such  as  a  discission  would 
be  deemed  inadvisable. 

Before  attempting  this  operation,  however,  there  are 
many  things  to  consider.  Should  the  fundus  be  dis- 
eased or  the  optic  nerve  atrophied,  the  operation  would 
be  of  no  practical  value.  To  determine  whether  the 
fundus  is  normal  the  animal  should  be  placed  in  a  dark- 
ened room,  the  better  eye  covered,  and  light  from  a 
small  mirror  reflected  on  the  eye  being  tested.  Note  the 
action  of  the  pupil,  and  whether  the  animal  notices  the 
light  as  it  is  placed  at  various  points  of  the  fields — above, 
below,  outward,  and  inward.  If  the  pupil  reacts,  and 
10 


146  OPHTHALMOLOGY  FOR  VETERINARIANS 

notice  is  taken  of  the  movements  of  light  by  motion  of 
the  eyeball,  it  is  fairly  conclusive  that  the  fundus  is 
normal. 

The  conjunctiva  must  be  free  from  secretion  and  the 
nictitans  membrane  and  lacrimal  apparatus  free  from 
hypertrophy  and  inflammation.  In  man  the  urine  is 
always  examined  to  determine  the  absence  of  albumin 
and  sugar.  The  animal  should  be  free  from  cough  and 
any  disease  which  may  cause  sudden  exertion.  The 
bowels  should  be  freely  opened  the  day  before  the 
operation. 

Preceding  the  operation  the  conjunctival  sac  should 
be  examined,  and  washed  with  a  saturated  solution  of 
boric  acid  or  a  i  :  5000  solution  of  corrosive  sublimate. 
The  long  hair  about  the  eye  may  be  trimmed  with 
scissors,  and  the  parts  washed  with  soap  and  water, 
followed  with  one  of  the  above  solutions. 

In  man  we  use  cocain  of  about  5  per  cent,  solution, 
but  in  animals  it  is  better  to  use  complete  general 
anesthesia,  as  any  sudden  movement  during  the  opera- 
tion may  cause  a  serious  accident. 

The  various  steps  of  the  operation  are:  Applying  the 
speculum,  corneal  section,  iridectomy,  cutting  the 
capsule,  extracting  the  lens,  cleansing  the  wound 
(toilet),  applying  the  dressing. 

Some  operators  prefer  to  use  atropin  previous  to 
the  operation  to  dilate  the  pupil.  Some  also  prefer 
not  to  use  the  speculum,  but  rather  to  have  a  com- 


OPERATIONS  FOR  CATARACT         147 

petent  assistant  hold  the  Hds  open  with  the  fingers  or 
retractors.     There  are  objections  to  this  latter  method, 
however,  as  the  hands  of  an  extra  person  are   always 
in  the  way,  and   pressure   upon  the  eyeball  may  be 
made,   which  must,  in    all    cases,   be    avoided.      The 
conjunctiva   of  the   globe  must  be   grasped  with  the 
fixation   forceps   at   a   point    opposite   to   the   corneal 
section.    The  Graefe  cataract  knife  may  then  be  passed 
in  at  the  corneal  margin,  sliding  it  along  through  the 
anterior    chamber,   being    careful    not   to   wound   the 
iris,  and  the  counterpuncture  made  at  a  point  directly 
opposite,  at  the  margin;  carry  the  blade  forward,  and 
with  one  sweep,  if  possible,  complete  the  section,  fol- 
lowing the  margin  all  the  way  as  closely  as  possible. 
The  success  of  this  step  depends  upon  two  principal 
points— the  skill  of  the  operator  and  an  exceedingly 
sharp  knife.     Each  knife  should  be  tested  before  the 
operation,  and  the  point  should  pass  through  the  test- 
drum  head  by  virtue  of  its  own  weight. 

In  man  the  corneal  section  is  usually  made  upward, 
passing  the  knife  through  the  cornea  from  the  external 
portion  in  each  eye,  making  the  counterpuncture  toward 
the  nose.  A  section  of  a  httle  more  than  one-third  of 
the  cornea  is  usually  made.  It  is  better  to  make  a  large 
rather  than  a  too  small  section,  so  that  the  lens  can  be 
readily  extracted  without  undue  pressure  and  wound- 
ing of  iris  and  adjacent  structures,  when  there  is  less 
danger  of  inflammation  of  these  structures  following, 


148  OPHTHALMOLOGY  FOR  VETERINARIANS 

also  less  danger  of  complications  attending  the  opera- 
tion. The  section  should  be  made  by  a  pushing  or  pull- 
ing movement,  with  as  little  sawing  motion  as  possible, 
as  there  is  less  danger  of  serration  of  the  edges  of  the 
wound,  and  healing  takes  place  more  readily.  When  one 
considers  the  anatomic  relations,  it  will  be  seen  that 
the  margin  of  the  cornea  must  be  closely  followed. 

Iridectomy  is  the  next  step,  though  this  is  omitted 
in  simple  extraction.  With  an  iridectomy  there  is  less 
danger  of  prolapse  of  the  iris  through  the  wound,  and 
the  lens  is  delivered  more  readily.  On  the  other  hand, 
the  pupil  is  less  regular  and  the  vision  may  not  be  as 
perfect,  though  just  as  good  visual  results  have  been 
attained  following  an  iridectomy  as  by  the  simple  ex- 
traction. 

Iridectomy  is  performed  by  passing  a  special  iris  for- 
ceps through  the  wound,  grasping  the  pupillary  border 
of  the  iris,  withdrawing  it  through  the  corneal  wound, 
and  snipping  off  a  small  portion  with  a  special  iris 
scissors. 

The  next  step  is  the  cutting  of  the  capsule.  Some 
operators  prefer  to  rupture  the  capsule  by  tearing  out 
a  portion  with  a  special  capsule  forceps.  A  much  better 
method  is  cutting  out  a  square  window  by  the  use  of 
the  capsulatome.  This  instrument  is  passed  in,  pushed 
downward,  then  horizontally,  then  upward,  then  again 
horizontally  to  the  starting-point.  This  square  section 
often  comes  away  with  the  lens,  leaving  a  clear  pupil. 


OPERATIONS  FOR  CATARACT  149 

The  next  step  is  the  extraction  of  the  lens.  With  a 
special  spoon-shaped  instrument  make  pressure  over 
the  cornea  at  a  point  about  three-fourths  of  the  corneal 
width,  in  the  opposite  direction  from  the  incision. 
This  causes  that  portion  of  the  lens  to  tilt  backward 
and  the  opposite  portion  to  tilt  forward  and  present  it- 
self in  the  wound.  CounterpressurQ  may  be  made  with 
a  small  spoon-shaped  instrument  on  the  sclera,  near 
the  corneal  section,  allowing  the  lens  to  sHde  over  this 
instrument,  with  which  its  delivery  may  be  greatly 
faciHtated  by  gently  Hfting  it  outward  and  upward,  at 
the  same  time  keeping  up  the  pressure  with  the  other 
instrument,  gradually  following  the  lens  upward  until 
its  extraction  is  completed.  Any  remaining  portions 
of  the  lens  substance  or  capsule  fragments  may  be 
teased  out  by  the  same  method. 

Protruding  portions  of  the  iris  must  be  replaced 
with  a  small  spatula  with  rounded  edges,  or  a  small 
shell-spoon,  and  all  blood-clots  and  shreds  must  be 
cleared  away  from  the  wound,  so  that  the  edges  will 
readily  unite.  The  speculum  may  then  be  removed 
and  the  eyelids  closed.  A  sterile  dressing  and  bandage 
must  then  be  apphed. 

Accidents  Attending  the  Operation. — Numerous  ac- 
cidents may  occur  during  the  course  of  the  operation. 
In  making  the  corneal  section  the  knife  may  be  caught 
in  the  iris,  in  which  case  it  may  be  gently  withdrawn 
until    disengaged    and    then    pushed    forward.       If    it 


I50  OPHTHALMOLOGY  FOR  VETERINARIANS 

cannot  be  disengaged  readily,  it  may  be  pushed  along, 
slightly  tilting  the  point  of  the  knife  forward,  until  it 
again  emerges  into  the  anterior  chamber,  to  the  op- 
posite corneal  margin  at  the  point  of  counterpuncture. 
This  accident  is  usually  due  to  a  shallow  anterior  cham- 
ber and  lack  of  skill.  Always  keep  the  knife-blade  in 
view,  in  the  anterior  chamber,  between  the  cornea  and 
the  iris.  When  the  iris  is  punctured  or  cut,  hemorrhage 
in  the  chamber  is  likely  to  follow.  This  occludes  one's 
vision,  but,  as  a  rule,  does  no  harm,  as  it  is  stroked  out 
with  the  lens  or  is  absorbed  soon  after  the  operation  is 
completed.  When  the  iris  is  cut,  an  iridectomy  will 
have  to  be  done  to  get  the  best  visual  results. 

Prolapse  of  the  iris  sometimes  occurs  when  a  large 
portion  of  this  body  passes  through  the  corneal  wound. 
In  the  majority  of  cases  this  can  easily  be  replaced 
by  the  shell-spoon  or  replacer.  If  it  cannot  be  so  replaced, 
it  must  be  grasped  with  the  iris  forceps  and  cut  off  near 
the  wound. 

The  lens  capsule  may  also  be  cut  in  the  passage  of  the 
knife  through  the  anterior  chamber.  This  weakens  the 
resistance,  and  pressure  of  the  lids  or  too  much  pres- 
sure upon  the  eyeball  with  the  fixation  forceps  may 
cause  the  lens  to  be  delivered  spontaneously  as  soon  as 
the  corneal  section  is  completed.  If  no  vitreous  follows 
this  accident,  the  operation  may  be  completed  in  the 
usual  way.  If  vitreous  escapes  when  the  lens  is  ex- 
tracted, the  speculum  should  be  immediately  removed 


OPERATIONS  FOR  CATARACT         15 1 

and  the  eye  closed.  After  a  minute's  rest  the  lid  may  be 
raised  with  the  finger,  and  the  escaping  portion  of 
vitreous  cut  away  with  a  pair  of  small  sharp  curved 
scissors.  The  lid  should  be  immediately  closed  and 
the  dressing  appHed,  but  too  much  pressure  over  the 
closed  Hd  must  be  avoided.  The  escape  of  a  Httle 
vitreous  does  no  special  harm,  but  the  loss  of  a  large 
quantity  lessens  the  support  of  the  retina,  and  it  may  be- 
come detached  from  its  normal  position. 

Iritis  and  cyclitis  follow  extraction  in  a  small  per- 
centage of  cases.  It  is  often  due  to  irritation  by  re- 
tained portions  of  the  lens  substance,  also  to  constitu- 
tional diseases,  and  severe  traimiatism  during  or  fol- 
lowing the  operation.  The  condition  must  be  met  by 
the  use  of  atropin  and  the  usual  treatment  for  iritis. 

Delayed  healing  of  the  wound  sometimes  occurs, 
even  when  the  wound  is  free  from  capsule,  lens,  or 
vitreous  substance.  Spasmodic  contraction  of  the  lids, 
too  great  pressure  of  the  bandage,  and  supervening 
glaucoma  must  be  looked  for.  If,  after  these  conditions 
have  been  corrected,  the  wound  still  gaps,  the  edges 
may  be  touched  with  the  silver  nitrate  stick. 

Dressing.— A  light  pad  of  absorbent  gauze  should  be 
placed  over  the  eye  and  retained  with  strips  of  adhesive 
plaster.  It  is  well  to  place  a  layer  of  absorbent  cotton 
between  the  layers  of  gauze.  Over  this  a  suitable 
metalHc  mask  may  be  placed  to  prevent  the  eye  from 
injury  in  the  act  of  rubbing.     The  mask  should  be 


152  OPHTHALMOLOGY  FOR  VETERINARIANS 

large  enough  to  rest  on  the  bony  structures  about  the 
eye  and  not  on  the  eye  itself.  It  may  be  sewed  into  a 
canvas  or  leather  support,  and  this  fastened  over  the 
ears  and  under  the  jaw  by  means  of  buckled  straps. 

In  the  human  subject  some  surgeons  let  the  dressing 
remain  five  days  before  removing  it,  when  the  wound 
will  be  healed.     Others  prefer  to  dress  the  eye  and  ex- 


Fig.  32. — Simple  eye-protector  for  horse.     Buckles  on  the  ends  of  the 
straps  are  not  shown. 

amine  it  every  day.  There  are  some  objections  to 
both  these  methods.  If,  after  twenty-four  to  forty-eight 
hours,  the  animal  has  done  itself  no  injury,  and  there  is 
no  evidence  of  secretion  on  the  dressing  next  the  eye, 
it  should  be  disturbed  as  little  as  possible.  If  there  be 
secretion  present,  a  clean  dressing  should  be  replaced, 
after  gently  washing  the  closed  lids  with  a  warm  boric 
acid  solution. 


OPERATIONS  FOR  CATARACT  153 

One  will  have  to  use  much  judgment  in  each  case  as 
to  his  after-treatment,  which  will  depend  greatly  upon 
his  knowledge  of  existing  conditions,  and  the  result  of 


Fig.  33- — Brusasco's  eye-protector  for  the  dog. 

an  operation  will  depend  very  largely  upon  such  knowl- 
edge and  skill. 

If  the  pupil  is  clear,  and  there  is  no  evidence  of  cap- 
sular and  iritic  adhesions  in  the  pupillary  area,  the  vision 


if 

Fig.  34. — Brusasco's  eye-protector  applied. 

will  be  fair.     Of  course,  we  must  always  take  into  ac- 
count the  refraction  of  the  lens  which  has  been  re- 


154  OPHTHALMOLOGY  FOR  VETERINARIANS 

moved.  In  man,  this  can  be  replaced  by  a  glass  lens  in 
front  of  the  eye,  but  in  animals  this  is  altogether  out  of 
the  question  at  the  present  time.  However,  where  the 
animal  was  once  blind,  it  can  now  see  enough  to  travel 
about,  though,  if  of  a  highly  nervous  temperament,  it 
may  shy  until  it  becomes  accustomed  to  its  changed 
condition. 


CHAPTER  XIV 
RECURRENT   OPHTHALMIA 

Recurrent  ophthalmia  is  commonly  known  as 
''moon  blindness"  and  periodic  ophthahnia.  It  has  no 
relation  to  the  moon's  changes,  but,  being  subject  to 
periodic  attacks,  it  has  been  known  by  the  latter  name. 

It  seems  to  be  particularly  confined  to  the  horse,  and 
the  favorite  site  of  inflammation  is  the  uveal  tract, 
though  the  whole  structure  of  the  eye  may  be  involved. 
An  initial  attack  may  apparently  get  well,  but  in  the 
course  of  thirty  to  ninety  days  it  may  recur,  and  if 
these  recun-ences  continue  the  eye  may  be  eventually 

lost. 

The  true  cause  of  the  disease  is  not  known,  though 
it  is  supposed  to  be  of  bacterial  origin.  Koch  found 
cocci  in  the  aqueous,  which  when  injected  into  the 
normal  eye  of  a  horse  produced  a  typic  ophthahnia 
with  the  loss  of  the  eye.  Other  investigators  have 
found  various  organisms,  but  none  has  been  definitely 
determined  to  be  the  specific  cause.  The  principal 
predisposing  cause  is  heredity.  Law  says,  'This  heredi- 
tary susceptibihty  is  so  strong  and  pernicious  that  in- 
telligent horsemen  everywhere  refuse  to  breed  from  a 

155 


156  OPHTHALMOLOGY  FOR  VETERINARIANS 

mare  that  has  once  suffered  from  recurrent  ophthalmia, 
and  at  the  government  studs  in  France  not  only  is  every 
unsound  stallion  rejected,  but  the  service  of  a  healthy 
stalHon  is  refused  to  any  mare  which  has  suffered  from 
disease  of  the  eyes.  A  consideration  for  the  future  of 
our  horses  would  demand  that  no  staUion  shall  stand 
for  the  pubhc  service  of  mares  unless  he  has  been  ex- 
amined and  licensed  as  a  sound  animal."  The  months 
of  spring  have  some  influence  in  producing  an  attack, 
as  well  as  pasturing  on  swampy  lands,  damp  stabling, 
improper  and  overfeeding,  intestinal  irritation,  local 
irritants,  and  debiHtating  diseases.  These  may  all  be 
exciting  causes,  yet  there  must  be  some  specific  bac- 
terium which  is  the  primary  factor. 

Symptoms. — The  disease  first  shows  itself  by  local 
irritation  due  to  a  low  grade  of  uveitis,  with  a  faint 
whitish  flocculent  deposit  in  the  anterior  chamber. 
There  are  later  manifestations  of  iritis  and  cyclitis  with 
photophobia.  The  pupil  is  sluggish  in  its  action,  even 
when  mydriatics  are  employed.  Exudates  are  thrown 
off  from  the  iris  and  adjacent  body,  and  are  deposited 
in  the  dependent  portion  of  the  anterior  chamber. 
In  many  cases  a  lymph  deposit  is  diffused  through  the 
aqueous,  imparting  to  it  a  milky  appearance  and  en- 
tirely closing  from  view  the  pupillary  area.  The  cornea 
becomes  hazy  from  the  presence  of  this  material  on  its 
posterior  surface  and  from  cellular  infiltration.  If  the 
inflammation  is  not  too  severe,  it  ceases  in  from  twelve 


RECURRENT  OPHTHALMIA  157 

to  fifteen  days,  and  the  eye  resumes  its  normal  ap- 
pearance. During  this  period  of  quiescence  the  lesions 
due  to  the  initial  attack  may  be  noticeable.  In  from 
one  to  three  months  a  recurrence  will  take  place,  with 
much  greater  severity  than  the  former  attack.  All  the 
symptoms  of  a  severe  iridocyclitis  prevail,  together  with 
an  increase  of  the  intra-ocular  tension  (glaucoma)  and 
the  formation  of  an  opaque  lens  (cataract).  The  sclera 
about  the  ciliary  border  takes  on  a  different  aspect, 
being  dark  or  bluish-black  in  color.  The  vitreous  be- 
comes opaque,  and  after  two  or  more  attacks  symptoms 
of  degeneration  appear,  and  the  globe  becomes  shrunken 
and  is  apparently  retracted. 

The  disease  seems  to  be  most  formidable,  in  that  it  is 
not  satisfied  with  one  eye,  but  in  time  attacks  the  fellow 
eye  and  destroys  that  also  in  like  manner.  Whether  this 
is  due  to  sympathetic  involvement,  as  is  often  seen  in 
man,  which  is  reasonable  to  assume,  or  whether  it  is  due 
to  the  original  cause,  is  a  question.  The  fellow  eye  is 
sometimes  attacked  and  destroyed,  even  while  vision 
remains  in  the  eye  which  was  first  affected. 

Treatment  seems  to  be  of  little  value  in  most  cases. 
Local  conditions  should  be  met  by  proper  therapeutic 
measures,  together  with  the  observance  of  hygienic 
conditions  and  proper  feeding.  The  animal  should 
be  isolated  from  other  animals,  and  should  not  be  used 
for  breeding  purposes. 


CHAPTER  XV 

GLAUCOMA 

Glaucoma  is  characterized  by  an  increase  of  the 
intra-ocular  tension — that  is,  the  eyeball  is  harder  than 
normal,  and  its  hardness  may  continue  to  increase  until 
there  is  absolute  resistance  to  pressure  by  the  finger- 
tips. Make  a  practice  of  taking  the  tension  in  all  dis- 
eases of  the  eye  as  a  part  of  the  routine  examination, 
and  acquaint  yourselves  with  the  normal  tension  of  the 
eyes  of  different  animals.  This  is  done  by  pressing  the 
eyeballs,  above  the  cornea,  over  the  closed  lids,  with 
the  tips  of  the  index-fingers;  first  gently  pressing  with 
one  finger,  and  then  with  the  other,  as  in  testing  for 
fluctuation.  There  is  an  instrument  devised  for  this 
purpose,  called  a  tenometer,  but  with  practice  and  ex- 
perience the  finger-tips  are  reliable. 

The  cause  of  increased  tension  is  due  to  a  damming 
up  or  failure  of  the  lymphatics  to  perform  their  func- 
tion, the  principal  one  being  Schlemm's  canal,  located 
in  the  sclera,  just  anterior  and  external  to  the  spaces 
of  Fontana  or  the  filtration  angle  of  the  anterior  cham- 
ber. This  angle  is  adjacent  to  the  anterior  portion  of  the 
ciliary  body  and  the  root  of  the  iris.      For  this  reason 

158 


GLAUCOMA  159 

atropin,  or  any  other  agent  which  causes  a  thickening  of 
the  iris  at  this  point,  should  not  be  used  in  cases  of 
glaucoma  or  in  a  subject  predisposed  to  an  attack,  as  in 
the  first  instance  it  will  only  increase  the  trouble  and 
probably  ruin  the  eye,  and  in  the  second  instance  it  will 
induce  an  attack. 

The  simple  type  of  glaucoma  comes  on  very  gradually, 
is  not  accompanied  with  inflammation,  and  there  is 
Httle  or  no  pain.  It  occurs  in  both  eyes.  The  tension 
may  vary  at  different  tunes,  and  often  during  the  first 
stage  it  is  not  recognized.  As  the  condition  advances 
the  pupils  become  somew^hat  dilated  and  sluggish,  the 
cornea  is  clear  or  slightly  hazy.  The  visual  field  is  much 
contracted,  and  the  acuity  of  vision  is  greatly  reduced. 
The  intra-ocular  pressure  is  continuous  and  increases, 
and,  because  of  this,  the  weaker  portions  of  the  head 
of  the  optic  nerve  give  way  and  are  pushed  backward, 
and  by  an  ophthalmoscopic  examination  a  deep  cup- 
ping of  this  portion  of  the  nerve  can  be  seen.  The 
retinal  blood-vessels  seem  to  be  lost  at  the  margin  of 
the  disk,  caused  by  the  cupping  and  dipping  down  of 
the  vessels  at  this  point.  This  cupping  of  the  disk 
varies  in  degree,  according  to  the  duration  of  the  ten- 
sion. If  the  condition  is  not  checked,  vision  will  ulti- 
mately be  destroyed.  This  simj^e  type  of  glaucoma 
often  becomes  inflammatory  in  character. 

The  inflammatory  type  of  glaucoma  is  usually  ac- 
companied with  a  great  deal  of  pain,  which  may  be 


l6o  OPHTHALMOLOGY  FOR  VETERINARIANS 

confined  to  the  eyeball  or  the  region  about  the  eye. 
The  globe  is  reddened  and  the  large  episcleral  vessels 
are  engorged.  The  cornea  is  hazy  in  appearance,  and 
the  pupil  is  enlarged  and  sluggish.  The  anterior  cham- 
ber is  shallow  and  the  iris  is  pushed  forward.  The  prog- 
nosis is  extremely  bad. 

This  type  is  often  secondary  to  diseases  of  the  eye, 
such  as  iritis  with  adhesions,  hemorrhages  in  the  retina 
and  chorioid,  and  to  traumatism.  It  is  also  one  of  the 
conditions  which  accompanies  recurrent  ophthalmia  in 
the  horse. 

Treatment. — The  object  in  the  treatment  of  glaucoma 
is  to  reheve  the  pressure  from  Schlemm's  canal  and 
re-estabhsh  its  function.  In  order  to  do  this  with  a 
drug  we  must  use  a  myotic,  or  one  which  causes  a 
contraction  of  the  pupil.  Eserin  in  solution  of  J  to  ^ 
per  cent.,  or  pilocarpin  in  solution  of  i  per  cent.,  may  be 
dropped  into  the  eyes  three  times  daily.  In  simple 
glaucoma  this  treatment  is  about  all  that  is  necessary, 
though  it  will  have  to  be  continued  for  months  or 
perhaps  years. 

In  inflammatory  glaucoma  the  same  drugs  are  used, 
but  if  pain  exists,  as  it  most  always  does,  it  will  be 
necessary  to  do  an  iridectomy.  To  get  the  best  results 
a  broad  excision  of  the  iris  should  be  made  near  its  base 
or  root.  The  tension  is  often  immediately  reduced 
following  this  operation.  A  too  sudden  reduction  of 
the  tension  may  do  harm,  as  the  sudden  inrush  of  blood 


GLAUCOMA  l6l 

into  the  retinal  vessels  may  cause  them  to  give  way, 
and  an  intra-ocular  hemorrhage  will  be  the  result.  For 
this  reason,  before  doing  an  iridectomy,  it  is  better  to 
do  a  paracentesis,  and  allow  the  gradual  escape  of  the 
aqueous  and  a  gradual  lessening  of  the  tension. 
11 


CHAPTER  XVI 

INJURIES  OF  THE  GLOBE 

Injuries  of  the  eyeball  in  general  are  simple  con- 
tusions, with  rupture,  incisions,  punctures,  and  lacera- 
tions. 

Contusions  are  produced  by  a  blow  with  some  blunt 
object.  Simple  contusions  without  rupture  may  be  ap- 
parently tri\dal  or  much  damage  may  be  done.  The 
results  of  simple  contusions  are  paralysis  of  the  sphincter 
pupillse,  causing  dilatation,  rupture  of  the  suspensory 
ligament,  dislocation  of  the  lens,  rupture  of  the  border 
of  the  iris,  causing  a  separation  and  an  opening  (irido- 
dialysis),  hemorrhage  in  the  anterior  chamber,  sub- 
conjunctival hemorrhage,  rupture  of  the  chorioid,  and 
hemorrhage  in  the  chorioid  and  retina.  Contusions  with 
rupture  of  the  globe  is  a  frequent  occurrence.  Usually 
the  rupture  takes  place  about  the  sclerocorneal  margin 
anteriorly.  It  may  occur  at  any  point,  according  to  the 
direction  of  the  blow.  The  posterior  portion  of  the 
globe  may  also  be  ruptured  in  an  irregular  manner,  and 
a  general  rupture  and  displacement  of  the  internal  struc- 
tures may  occur.  The  following  case,  in  a  colored  man, 
is  a  good  illustration:  The  man  was  struck  with  con- 

162 


INJURIES  OF  THE  GLOBE  163 

siderable  force  by  a  billiard  ball  in  the  left  eye.  He 
was  seen  twelve  hours  after  the  accident.  The  lids  were 
badly  swollen,  the  eye  closed.  Inspection  revealed  a 
rupture  of  one-third  of  the  cornea  near  the  inner  margin. 
The  anterior  chamber  was  filled  with  blood;  the  cornea 
was  clear.  The  case  was  nursed  along  with  cold  anti- 
septic applications  until  the  swelling  subsided.  The  cor- 
neal rupture  failed  to  heal  readily,  still  there  was  no 
prolapse  of  the  internal  structures.  After  two  weeks' 
treatment,  when  efforts  seemed  to  be  of  no  avail  in 
saving  vision,  the  eye  was  enucleated.  The  globe  was 
found  to  have  been  ruptured  posteriorly  at  a  point  op- 
posite to  the  anterior  rupture,  but  much  more  extensive 
and  in  a  crescentic  shape,  nearly  three-fourths  around  the 
globe.  This  posterior  rupture  had  readily  healed;  the 
sclera  was  firmJy  united.  This  goes  to  show  that  the 
remote  rupture  is  often  more  extensive  than  that  where 
the  blow  was  received.  In  this  case  the  lens  was  dislo- 
cated and  the  iris  torn.  About  the  anterior  rupture  the 
cornea  was  partly  opaque  or  white  in  appearance.  Had 
the  globe  been  allowed  to  remain  in  the  orbit  it  would 
have  been  of  no  value,  as  its  function  was  destroyed. 
The  globe  would  have  shriveled  (phthisis  bulbi),  and 
there  would  probably  have  been  subsequent  attacks  of 
inflammation. 

Punctures  of  the  globe  are  caused  by  pointed,  sharp, 
or  dull  objects,  and  the  result  depends  upon  the  location, 
depth,  and  the  condition  of  the  object— that  is,  whether 


1 64  OPHTHALMOLOGY  FOR  VETERINARIANS 

it  is  clean  or  dirty.  Even  if  an  object  is  apparently  clean, 
it  may  carry  bacteria  with  it  into  the  eye  and  produce 
terrific  reaction.  Punctures  through  the  cornea  produce 
a  loss  of  the  aqueous  and  often  a  prolapse  of  the  iris  into 
the  wound,  which  may  become  adherent  (anterior  syne- 
chiae)  and  interfere  with  the  normal  pupillary  reaction, 
or  the  iris  is  drawn  to  one  side,  producing  an  irregular 
pupil.  Punctures  still  deeper  cause  hemorrhage  in  the 
anterior  chamber  by  ruptures  of  the  iris  vessels.  Be- 
sides these,  the  lens  becomes  cataractous  through 
rupture  of  its  capsule.  The  lens  often  swells,  and  all 
the  symptoms  of  glaucoma  accompany  the  accident. 

A  puncture  of  the  ciHary  body  by  a  septic  object 
should  always  be  regarded  with  apprehension.  Pro- 
lapse of  the  internal  structures  of  the  globe  will  depend 
upon  the  size  of  the  puncture  and  the  resistance  of  the 
external  coats.  Small  punctures  of  the  sclera  posterior 
to  the  ciHary  region  are  usually  unimportant  from  a 
surgical  point  of  view,  though  they  often  produce  hem- 
orrhage within  the  eyeball  and  a  localized  scotoma. 

The  results  of  an  incision  are  very  much  the  same  as 
those  of  a  puncture,  though  there  is  more  probability 
of  a  better  and  more  rapid  union  of  the  wound  by  sutur- 
ing the  same. 

Lacerations  are  probably  the  most  severe  type  of 
injuries  to  the  globe.  The  result  of  a  laceration  depends 
upon  the  extent  and  the  part  injured. 

Injuries  are  nearly  always  confined  to  the  anterior 


INJURIES  OF  THE  GLOBE  165 

portion  of  the  globe.  A  laceration  heals  much  less 
readily  than  an  incision,  and  is  more  liable  to  infection 
because  of  the  ragged  edges  of  the  wound.  Practically 
the  same  conditions  of  prolapse,  dislocation  of  the 
internal  structures,  etc.,  take  place  in  extensive  lacera- 
tions as  in  punctures  and  incisions. 


Fig.  35. — Injury  of  the  globe,  two  months'  standing.  The  contents 
of  the  globe  prolapsed.  Enucleation  was  done  and  an  artificial  eye 
appHed  in  due  season.     (Dr.  Banner's  case.) 

Complications. — In  severe  injuries  of  the  globe  the 
neighboring  structures  may  be  involved.  The  lids  may 
be  badly  bruised,  swollen,  and  ecchymosed;  or  they 
may  be  punctured,  incised,  or  lacerated.  The  bones  of 
the  orbit  may  be  fractured  and  displaced.  The  optic 
nerve  may  be  ruptured,  or  atrophy  follows  because  of 


1 66  OPHTHALMOLOGY  FOR  VETERINARIANS 

compression.  Cellulitis  of  the  orbital  tissues  may  follow 
from  infection. 

Treatment  of  Injuries  of  the  Globe. — The  main  object 
in  treatment  is  to  save  the  function  of  the  eye.  If  vision 
cannot  be  saved,  our  next  object  is  to  preserve  the  globe. 
In  cases  where  much  damage  has  been  done,  the  vision 
destroyed,  and  the  eye  is  unsightly,  the  most  philosophic 
method  would  be  to  enucleate  the  globe  and  replace  it 
with  an  artificial  eye;  but,  for  reasons  unknown  to  the 
profession,  an  eyeball  is  often  preserved  when  it  is  of 
no  earthly  use,  and  often  when  its  ugliness  is  most  con- 
spicuous to  friends  and  passers  by. 

Always  remember  the  general  principles  of  cleanliness 
and  asepsis  in  the  treatment  of  all  these  cases.  Wounds 
should  be  cleansed  of  all  foreign  substances,  for  the 
danger  of  infection  is  often  greater  than  that  of  the 
injury  itself. 

Simple  abrasions  of  the  cornea,  from  blows  of  twigs 
or  other  objects,  should  be  treated  with  applications  of 
mild  antiseptic  washes,  and  an  aseptic  pad  and  bandage 
appHed  for  protection.  These  superficial  abrasions  heal 
rapidly,  and  the  epithelium  is  soon  re-estabhshed  if  the 
wound  is  not  infected.  If  the  wound  becomes  infected, 
infiltration  and  ulceration  of  the  cornea  may  follow, 
when  the  treatment  would  be  the  same  as  given  under 
Ulceration  of  the  Cornea. 

Perforating  wounds  of  the  cornea,  in  which  the 
aqueous  escapes  and  the  iris  is  caught  in  the  wound, 


INJURIES  OF  THE  GLOBE  167 

require  special  treatment.      After  thoroughly  cleansing 
the  wound,  the  iris,  if  not  wounded  itself,  may  be  re- 
placed, and,  if  it  is  centrally  located,  a  mydriatic  should 
be  employed  to  draw  it  away  from  the  opening  and 
prevent  adhesions.     If  the  wound  is  near  the  corneal 
margin  a  myotic  may  be  used  for  the  same  purpose. 
If  the  wound  is  extensive,  and  involves  the  iris  with  a 
protrusion  of  this  tissue  through  the  wound,  the  pro- 
truding portion  may  be  excised  and  a  mydriatic  or  myotic 
employed,  according  to  the  location  of  the  injury.    By 
watching   the   condition   of   the  iris,   and  keeping  the 
wound   absolutely  clean  and  protected  with  an  anti- 
septic dressing,  nature  will  produce  wonderful  results 
oftentimes  in  these  cases.    It  is  not  advisable  to  stitch 
a  corneal  wound. 

If  inflammation  arises  by  reason  of  infection,  more 
rigid  antiseptic  measures  must  be  employed.  After 
thoroughly  cleansing  the  eye  of  all  secretion  the  insuffla- 
tion of  finely  powdered  iodoform,  boric  acid,  or  equal 
parts  of  these  may  be  used,  or  an  ointment  of  iodoform, 
with  lanolin  as  a  base,  is  of  great  value.  Should  inflam- 
matory reaction  of  the  iris  take  place  the  general  treat- 
ment of  iritis  must  be  employed. 

Wounds  of  the  conjunctiva  and  sclera  may  be  brought 
together  with  fine  sutures.  It  is  preferable  to  use  a 
silk  suture  with  a  needle  on  both  ends,  and  these  passed 
through  the  tissue  from  within  outward,  the  sclera  and 
conjunctiva  stitched  separately.     The  ruptured  parts 


1 68  OPHTHALMOLOGY  FOR  VETERINARIANS 

should  be  brought  together  evenly,  and  strict  caution 
should  be  observed  that  none  of  the  internal  structures 
be  caught  in  the  inclosed  wound.  In  all  hopeless  cases, 
more  particularly  when  there  is  danger  of  sympathetic 
inflammation  of  the  other  eye  arising,  the  globe  should 
be  enucleated. 

Injuries  of  the  Globe,  with  Foreign  Bodies  Remaining 
in  the  Eye. — These  are  always  to  be  looked  upon  with 
considerable  apprehension.  Such  bodies  may  be  small 
or  large,  sharp  or  blunt.  A  small  sharp-pointed  body 
may  enter  the  eye  and  its  place  of  entrance  be  hardly 
noticeable.  Again,  the  body  may  be  large  enough  to 
lacerate  the  globe.  If  the  smaller  body  carries  bacteria 
with  it,  it  may  do  as  much  or  more  damage  eventually 
than  the  larger  body.  These  foreign  bodies  are  com- 
posed of  various  substances,  such  as  stone,  glass,  wood, 
lead,  copper,  iron,  and  steel.  The  wound  is  much  like 
that  of  a  puncture  plus  the  presence  of  the  foreign  body. 
There  is  great  danger  of  infection  and  irritation  of  the 
tissues  in  contact  with  the  foreign  body. 

It  is  always  advisable  to  remove  a  foreign  body  if  it 
can  be  located  and  readily  reached.  If  the  body  is  in 
the  anterior  chamber,  it  may  be  withdrawn  through  its 
source  of  entrance  with  a  small  forceps.  If  it  has  passed 
into  the  vitreous,  it  maybe  necessary  to  make  an  incision 
in  the  sclera  and  remove  it  through  that  opening. 

When  the  media  are  clear,  the  body  may  be  seen  with 
the  ophthalmoscope.    If  it  is  a  substance  which  will  react 


INJURIES  OF  THE  GLOBE  169 

to  magnetic  attraction,  the  electromagnet  is  the  instru- 
ment to  use.  It  is  made  in  two  forms— the  large  or 
giant  magnet,  which  has  a  lifting  power  of  400  pounds 
or  more,  and  the  hand  magnet,  which  is  sufficient  in 
most  cases. 

In  making  the  scleral  incision  the  eye  should  be  drawn 
in  the  opposite  direction,  by  an  assistant,  with  a  strong 
fixation  forceps.  Plunge  the  Graefe  knife  into  the  eye 
with  the  edge  of  the  blade  backward,  and  enlarge  the 
opening  in  the  act  of  withdrawing  the  knife.  The  in- 
cision should  be  made  far  enough  back  to  prevent 
wounding  the  lens  or  cihary  body,  and  in  a  position  as 
near  the  foreign  body  as  possible.  The  magnet  point 
is  now  introduced  into  the  wound  and  the  current 
turned  on.  The  body  will  usually  come  in  contact  with 
the  point,  when  it  can  be  withdrawn.  Authors  gener- 
ally recommend  making  the  scleral  incision  at  a  point 
between  the  insertion  of  the  muscles,  but  the  writer  has 
made  the  incision  through  the  belly  of  the  internal 
rectus  muscle  in  one  case,  and  was  successful  in  remov- 
ing steel  from  the  vitreous  without  the  loss  of  a  particle 
of  vitreous  or  injury  to  the  cihary  body  or  lens.  Such 
an  incision  must  be  made  parallel  to  the  muscle-fibers, 
which  close  and  protect  the  scleral  wound. 

When  the  body  is  embedded  in  the  chorioid  it  may 
become  encysted,  and,  if  sterile,  may  do  no  particular 
harm,  though  it  may  be  dislodged,  drop  into  the  vitreous, 
and  cause  irritation  and  inflammation.    If  lodged  in  the 


I70  OPHTHALMOLOGY  EOR  VETERINARIANS 

lens,  it  may  also  do  no  harm  for  a  time,  except  to  pro- 
duce a  traumatic  cataract,  though  the  lens  may  swell 
and  glaucomatous  symptoms  follow;  or  the  lens,  in  young 
subjects,  may  become  gradually  absorbed,  and  the  body 
will  drop  down,  irritate  the  cihary  body,  and  produce 
cycHtis,  iritis,  chorioiditis,  etc. 

Enucleation  of  the  Globe. — As  before  stated,  it  is 
better,  in  all  hopeless  cases,  to  enucleate  the  globe. 
This  is  much  more  difhcult  to  do  in  the  quadruped  than 
in  man,  because  of  the  large  retractor  muscle.  The 
steps  of  the  operation  are  as  follows: 

General  anesthesia  should  be  used  in  all  cases,  as  we  are 
not  justified  in  causing  the  dumb  beast  to  suffer  more 
pain  than  is  necessary.  Wash  the  eye  and  the  surround- 
ing parts  with  soap  and  water,  followed  by  an  antiseptic 
solution.  Apply  the  speculum,  or  have  an  assistant 
hold  the  Hds  open  with  retractors.  Make  an  incision 
through  the  conjunctiva,  around  the  corneal  margin, 
preserving  as  much  of  the  tissue  as  possible.  Under- 
mine the  conjunctiva  as  far  back  as  the  insertion  of  the 
muscles,  keeping  as  close  to  the  sclera  as  possible. 
Pick  up  the  muscles  individually  with  the  tenotomy 
hook,  and  cut  them,  with  the  small  curved  scissors, 
near  their  tendinous  insertion.  Cut  away,  gradually, 
the  insertion  of  the  retractor  muscle,  then  pass  in  the 
strong  curved  scissors,  grasp  the  optic  nerve,  and 
divide  it  with  one  snip  if  possible.  In  doing  this  the 
handle  of  the  scissors  must  be  raised,  not  lowered,  as 


INJURIES  OF  THE  GLOBE 


171 


there  is  danger  of  cutting  the  sclera  itself.  The  globe 
can  then  be  gradually  pried  out  and  any  adhesions  cut 
away. 

When  the  globe  has  been  removed,  the  hemorrhage 
can  easily  be  stopped  by  placing  a  dry  aseptic  gauze 


Fig.  36. — Enucleation  of  the  eye.  This  is  an  old  method  and  is  used 
today  by  many  operators.  •  It  seems,  however,  that  the  use  of  ether,  the 
relief  of  pain,  and  more  careful  dissection  would  be  a  more  scientific  and 
humane  procedure. 


within  the  capsule.  When  hemorrhage  has  ceased, 
withdraw  the  gauze  and  close  the  eye,  when  the  tis- 
sues will  contract  and  come  together  naturally.  Some 
surgeons  close  the  wound  with  a  puckering  suture 
through  the  conjunctiva,  but  this  is  hardly  necessary 


172  OPHTHALMOLOGY  FOR  VETERINARIANS 

in  the  animal.  It  is  well  to  place  some  absorbent 
powder  on  the  fissure  and  apply  a  compress  bandage. 

Healing  takes  place  readily,  and  a  good  stump  is 
soon  formed  for  an  artificial  eye.  These,  for  the  animal, 
are  usually  made  of  hard  rubber,  as  they  are  less  easily 
broken,  and  the  coloring  conforms  more  to  animals' 
eyes  than  those  made  of  glass. 

An  artificial  eye  should  not  be  placed  until  the  wound 
is  healed  and  there  are  no  inflammatory  symptoms 
present. 

Prolapse  of  the  Eyeball. — It  is  understood  by  some 
of  the  laity  that  "the  eyeball  can  be  taken  out,  scraped, 
and  put  back  again  into  the  orbit."  Any  one  with  a 
knowledge  of  the  eyeball  and  its  muscular  attachments 
can  readily  see  the  folly  of  this  assumption.  In  the 
dog,  however,  the  eyeball  is  not  held  very  securely 
in  the  orbit,  because  the  anterior  bony  arch  is  wanting, 
and  the  eyeball  is  supported  only  by  the  ligamentous 
attachments  and  the  lids.  For  this  reason,  the  eyeball 
of  the  dog  is  often  prolapsed  or  dislocated  forward  by 
traumatism.  It  is  said  also  to  prolapse  by  reason  of 
inflammatory  processes  within  the  globe,  but  this 
cause  must  be  exceedingly  rare.  It  is  more  probable  that 
progressive  tumors  within  the  orbit  might  be  the  cause. 

Prolapse  of  the  eyeball  presents  a  very  peculiar  and 
ugly  appearance.  The  writer  once  saw  an  English  bull- 
dog whose  eyeball  was  dislocated  outward  and  down- 
ward by  fighting  with  another  dog.    It  was  held  in  this 


INJURIES  OF  THE  GLOBE  173 

condition  by  contraction  of  the  orbicularis  palpebrarum. 
This  was  a  simple  dislocation,  without  rupture  of  the 
conjunctiva  or  any  of  the  muscles  of  the  globe. 

Treatment. — If  the  eye  cannot  be  readily  put  back 
into  place,  it  will  be  necessary  to  produce  general 
anesthesia  in  order  to  allay  the  sensitiveness  of  the 
cornea  and  relax  the  contracted  muscles.  Then,  with 
gentle  pressure  with  the  thumbs  and  fingers  over  the 
outer  and  inner  portions  of  the  globe  (avoiding  pressure 
on  the  cornea),  reduce  it  to  its  normal  position.  If 
you  fail  in  doing  this,  make  traction  of  the  upper  Hd 
outward  with  an  elevator.  If  you  still  fail  to  reduce  it, 
the  outer  tendon  of  the  orbicularis  may  be  divided, 
when  it  can  readily  be  reduced.  This  must  be  brought 
together  again  with  sutures  in  order  to  support  the 
globe,  or  it  may  be  again  dislocated  spontaneously. 
If  too  long  a  time  elapses  before  the  reduction  of  the 
globe,  the  cornea  becomes  dry  and  hazy  by  reason  of 
exposure.  It  soon  resumes  its  normal  transparency, 
but  if  it  does  not  it  must  be  treated  as  a  superficial 
keratitis. 


CHAPTER  XVII 

FRACTURE  OF  THE  ORBIT 

Fracture  of  the  orbit  takes  place  usually  near  the 
orbital  ridge  of  the  frontal  bone,  though  any  bone  of  the 
orbit  is  subject  to  fracture  by  direct  injury  or  concussion. 

Homed  animals  receive  such  injuries  by  fighting  with 
other  animals,  or  the  injury  may  be  self-inflicted  while 
suffering  with  colic  and  other  severe  pain. 

When  fracture  of  the  orbital  ridge  takes  place,  crepita- 
tion may  be  felt  while  manipulating  the  parts,  or  the 
fractured  part  may  be  entirely  displaced  and  deformity 
result.  Fracture  of  the  inner  walls  of  the  orbit  may 
result  in  blindness  (amaurosis)  of  the  eye  by  pressure 
upon  the  optic  nerve.  Celluhtis  and  abscess  of  the 
orbital  tissue  may  follow  fractures  caused  by  penetrat- 
ing wounds. 

Treatment. — Cold  applications  to  prevent  or  reduce 
swelling  and  inflammation.  Remove  all  dirt  and  foreign 
substances  from  the  wound  and  apply  antiseptic  dress- 
ings. If  an  abscess  forms,  it  must  be  drained  externally 
by  opening  the  wound  with  an  aseptic  probe.  The  wound 
must  be  kept  open,  and  this  can  be  done  by  placing  in  it 
a  small  wick  of  iodoform  gauze,  which  may  be  held  in 
place  with  aseptic  absorbent  gauze  and  bandage. 

174 


FRACTURE  OF  THE  ORBIT  175 

When  atrophy  of  the  optic  nerve  takes  place  from 
pressure,  very  Httle  can  be  done.  If  celluHtis  and  ab- 
scess are  not  controlled  by  the  above  measures,  it  will 
be  necessary  not  only  to  enucleate  the  eyeball,  but, 
in  many  cases,  to  cut  away  all  the  tissues  in  the  orbit 
(exenteration),  as  the  pus  may  burrow  through  the 
sclera,  causing  a  panophthalmitis,  or  it  may  endanger 
life  by  extending  to  the  meninges  of  the  brain. 


CHAPTER  XVIII 

PARASITES  OF  THE  EYE 

Parasites  of  the  Eyelids. — The  eyelids  are  subject 
to  the  invasion  of  various  parasites  as  follows: 

Pediculi  {Lice). — These  are  often  seen  along  the 
margin  of  the  Hds  when  present  on  other  portions  of 
the  body. 

The  eggs  are  found  embedded  or  deposited  near  the 
lashes,  and  are  often  covered  with  crusts  resulting  from 
the  secretion  caused  by  their  irritation.  They  produce 
a  marginal  blepharitis.  The  crusts  should  be  softened 
with  the  yellow  oxid  of  mercury  ointment  and  removed. 
A  piece  of  absorbent  cotton,  dipped  in  absolute  alcohol 
and  gently  rubbed  over  the  hds,  will  catch  and  remove 
the  hce  and  their  eggs. 

The  Filaria  palpebralis,  discovered  as  early  as  1429 
on  the  conjunctiva  of  the  horse,  is  a  cylindroid  worm, 
8  to  15  mm.  long,  and  thin  at  the  extremities. 

The  presence  of  this  parasite  causes  an  inflammation, 
varying  from  a  slight  to  a  severe  conjunctivitis,  with 
swollen  and  painful  lids. 

Law  mentions  a  case  in  which  ''the  lids  were  firmly 
closed,  the  flow  of  tears  abundant;  the  cornea  was  vas- 

176 


PARASITES  OF  THE  EYE  177 

cular  in  its  outer  portion,  with  a  surrounding  area  of 
opacity,  which  was  followed  with  a  bluish-white  opacity 
of  the  whole  cornea  excepting  the  inner  can  thus.  Under 
treatment  there  was  a  general  improvement,  but  a  month 
later  there  was  a  new  attack,  and  five  filaria  were  dis- 
covered under  the  eyehds.  The  cornea  became  opaque 
and  permanent  blindness  ensued." 

In  some  cases  there  are  no  symptoms  to  indicate  the 
presence  of  the  parasites.  The  only  way  to  diagnose 
the  trouble  is  in  finding  the  worms,  and  in  many  in- 
stances this  is  not  an  easy  thing  to  do,  as  they  may  be 
concealed  within  the  conjunctival  folds,  and  are  not 
sufficiently  active  unless  the  surfaces  are  quite  moist. 

Filaria  Lacrimalis  Bovis. — This  resembles  the  worm 
last  described.  The  female  is  from  20  to  24  mm.  in 
length.  It  is  usually  found  on  the  conjunctiva  at  the 
inner  angle. 

The  symptoms  excited  by  the  presence  of  this  para- 
site resemble  those  last  described — viz.,  a  certain 
amount  of  swelling  of  the  lids,  partial  ptosis  and  lacri- 
mation,  together  with  inflammation  of  the  conjunctiva 
and  cornea. 

The  worm  can  readily  be  seen  in  motion  on  a  moist 
eye  if  carefully  looked  for. 

The    Demodex    folliculorum,    commonly    called    the 
"pimple  mite,"  is  often  found  in  the  miebomian  glands 
of  the  horse,  dog,  and  sheep.      As  a  rule  it  does  not 
cause  any  marked  disturbance. 
12 


178  OPHTHALMOLOGY  FOR  VETERINARIANS 

The  Trombidium,  an  extremely  small  silky  worm, 
invades  the  margin  of  the  lids  of  the  dog.  Its  more  com- 
mon site  is  at  the  outer  and  inner  canthi.  The  symptoms 
produced^ by  this  are  not  marked. 

The  Trichina  is  said  to  have  been  found  in  the  muscles 
of  the  eyelids,  as  well  as  in  other  muscles  of  the  body. 
They  cause  swelHng  of  the  Hds  which  is  usually  pain- 
ful, conjunctivitis,  etc.  The  general  symptoms  of 
trichina  are  also  present. 

The  Hemopis  sanguisuga,  the  horse  leech,  has  been 
found  clinging  to  the  Hds  and  conjunctiva  of  the  horse 
under  favorable  conditions. 

Parasites  Found  Within  the  Eyeball.— The  Filaria 
oculi  equina,  also  known  as  the  Filaria  papulosa  and  the 
Filaria  pellucida.  This  is  not  infrequently  seen  in  the 
eye  of  the  horse.  It  was  known  as  early  as  the  seven- 
teenth century,  and  has  been  discovered  by  various 
observers  in  this  country  and  in  Europe. 

It  seems  to  be  more  prevalent  among  animals  which 
are  allowed  to  graze  in  wet  pastures  in  moderate  cli- 
mates. 

It  is  described  as  a  thread-like  worm,  from  22  to  35 
mm.  long,  the  male  being  the  longer,  with  spiral  tail, 
and  reddish- white  in  color. 

Law  describes  the  symptoms  as  follows:  ''Exception- 
ally the  worm  causes  no  inflammation,  and  it  can  be 
seen  actively  bending  and  unbending  itself  in  the  form 
of  a  loop,  a  figure-of-eight,  or  a  spiral,  in  the  anterior 


PARASITES  OF  THE  EYE  179 

chamber.  Usually  there  is  considerable  inflammation, 
closure  of  the  lids  and  watering  of  the  eyes,  redness  of 
the  mucosa,  clouding,  and  even  vascularity  of  the 
cornea.  Still,  in  a  majority  of  the  cases,  a  portion  of  the 
cornea  remains  sufficiently  transparent  to  allow  the 
movements  of  the  worm  to  be  seen.  Some  tunes  it  will 
temporarily  retreat  through  the  pupil  and  disappear 
behind  the  iris.  Sometimes  only  one  eye  is  involved,  in 
other  cases  both  eyes,  and  in  some  instances  two  or  even 
three  parasites  are  found  in  one  eye." 

If  the  worm  can  readily  be  seen  in  the  anterior  cham- 
ber, an  incision  may  be  made  in  the  margin  with  a 
cataract  knife,  when  the  worm  may  be  grasped  with  a 
small  pair  of  forceps  and  withdrawn.  Cocain  must 
be  used  to  anesthetize  the  cornea  and  strict  antisepsis 
observed.  Much  care  must  be  observed  not  to  wound 
the  iris  or  the  cornea  in  this  operation. 

The  Cysticercus  Cellulosa.— This  has  been  found  in 
various  portions  of  the  eye — in  the  vitreous,  the  chorioid, 
retina,  the  anterior  chamber,  the  muscles  of  the  globe, 
and  beneath  the  palpebral  and  bulbar  conjunctiva. 

It  has  been  found  in  the  eye  of  man,  the  horse,  the  dog, 
and  the  pig.  When  it  appears  in  the  outer  coats  of  the 
eye  it  is  described  as  a  white  ovoid  body.  Within  the 
vitreous  ''the  cysticercus  becomes  visible  as  a  bluish- 
white  bladder"  (Duane).  When  in  the  anterior  chamber 
it  has  the  appearance  of  a  white  cyst  upon  the  iris. 


l8o  OPHTHALMOLOGY  FOR  VETERINARIANS 

Within  the  eyeball  it  is  usually  stationary,  though  it  has 
been  seen  to  make  quick,  active  movements. 

Inflammation  of  the  internal  structures  usually  follow 
its  entrance  into  the  eye;  detachment  of  the  retina  and 
cataract  occur,  vision  is  eventually  lost,  and  the  globe 
becomes  atrophied. 

Attempts  have  been  made  to  remove  the  organism  by 
making  an  incision  in  the  sclera  and  grasping  it  with  a 
small  pair  of  forceps;  and,  if  it  is  in  a  position  where  it 
can  readily  be  reached,  this  may  be  done;  but,  in  the 
animal,  one  would  assume  a  great  risk  in  not  being  able 
to  grasp  it,  and  much  damage  would  be  done  the  globe 
in  making  the  attempt. 


CHAPTER  XIX 

THE  PRINCIPLES  OF  VISION 

Vision  is  dependent  upon  light.  Rays  of  light  from 
a  distance  are  parallel,  while  those  from  near  objects  are 
divergent. 

Refraction}  means  the  turning  or  bending  of  rays  of 
light  as  they  pass  through  an  object  that  is  denser  than 
the  air.  A  good  illustration  of  this  is  the  apparent  bend- 
ing of  a  spoon  upward  when  placed  in  a  glass  of  water,  or 
the  displacement  of  an  object  when  seen  through  a 
prism. 

The  index  of  refraction  is  the  resistance  of  the  object 
through  which  the  light  passes  as  compared  with  air, 
which  is  taken  as  i. 

When  parallel  rays  of  light  pass  through  a  plate-glass 
with  both  surfaces  parallel  they  are  not  refracted,  but 
emerge  as  they  entered,  but  when  they  pass  through  a 
glass  that  is  thicker  at  one  edge  than  the  other  (a  prism), 
they  are  deviated,  or  refracted  from  the  apex  toward  the 
base,  or  the  thicker  portion  of  the  prism.  The  angle  of 
refraction — that  formed  by  the  incident  ray  with  the 

^  Only  a  primary  description  of  refraction  will  be  considered.  For 
a  more  complete  study  of  refraction  of  light,  the  writer  would  refer  the 
student  to  some  good  work  on  physics. 

181 


1 82  OPHTHALMOLOGY  FOR  VETERINARIANS 

refracted  ray — depends  upon  the  strength  or  degree  of 
the  prism.    Prisms  are  numbered  from  J  degree  up. 

Spheric  lenses — those  cut  from  a  sphere — are  refrac- 
ting lenses.  The  convex  or  plus  spheric  lenses — of 
which  the  crystalline  lens  of  the  eye  is  a  type — collect 
rays  of  light  at  a  point  on  the  opposite  side;  while 
concave  or  minus  spheric  lenses  diverge  rays  of  Hght 
on  the  opposite  side.  Rays  passing  through  the  optical 
center  of  a  lens  are  not  refracted. 


Fig.  37. — Principal  focus  of  a  convex  lens.  The  parallel  rays  a,  h,  c,  d 
are  refracted  by  the  lens  so  as  to  unite  at  the  point  F  on  the  axis  P;  the 
ray  P  undergoes  no  refraction.  F  is  the  principal  focus,  (de  Schweinitz, 
"Diseases  of  the  Eye.") 

The  point  at  which  parallel  rays  are  collected  is  the 
principal  focus  of  the  lens.  The  distance  of  this  point 
from  the  optical  center  of  the  lens  depends  upon  the  radii 
of  curvature  and  its  index  of  refraction.  Rays  which 
diverge,  back  again  through  the  lens,  become  again 
parallel. 

When  rays  come  from  an  object  nearer  than  ^'infinity" 
— supposed  to  be  about  20  feet— they  diverge,  and  are 


THE  PRINCIPLES  OF  VISION  183 

collected  at  a  point  on  the  opposite  side  of  the  lens,  at  a 
greater  distance  from  the  optical  center  of  the  lens  than 
the  principal  focus.    The  nearer  the  object  is  to  the  lens, 


Fig.  38. — Conjugate  focus  of  a  convex  lens.  The  two  dots  in  the  axis 
represent  the  principal  foci,  one  being  marked  F.  Rays  diverging  from 
O  converge  after  refraction  to  the  point  F\  farther  than  the  principal 
focus.  Rays  from  F'  also  converge  after  refraction  to  0.  0  and  F  are 
conjugate  foci,     (de  Schweinitz,  "Diseases  of  the  Eye.") 

the  greater  is  the  divergence,  and  the  farther  is  the  con- 
vergence on  the  opposite  side.  These  two  points — the 
point  of  divergence  and  the  point  of  convergence — are 


Fig.  39. — Virtual  focus  of  a  convex  lens.  Rays  from  the  point  0, 
less  than  the  principal  focal  distance,  diverge  after  refraction  as  if  they 
came  from  the  point  V.  V  is  the  virtual  focus  of  O.  (de  Schweinitz, 
"Diseases  of  the  Eye.") 

known  as  the  conjugate  foci.  These  points  are  at  an 
equal  distance  when  the  point  of  divergence  is  at  a  dis- 
tance twice  the  focal  distance  of  the  lens. 


1 84  OPHTHALMOLOGY  FOR  VETERINARIANS 

The  virtual  focus  of  a  convex  lens  is  the  point  at  which 
rays  meet  in  a  backward  direction  on  the  same  side  of 


Fig.  40. — Principal  focus  of  a  concave  lens.  Parallel  rays  a,  b,  d,  e, 
after  refraction  by  the  concave  lens  L,  are  rendered  divergent  as  if  they 
came  from  the  point  F  on  the  axis  c.  The  ray  c  is  not  refracted.  F,  the 
principal  focus  of  a  concave  lens,  is  virtual,  (de  Schweinitz,  "Diseases 
of  the  Eye.") 


Fig.  41.— Virtual  image  of  a  convex  lens:  C,  D  is  the  object;  C,  D'  is 
the  virtual  image,  erect  and  magnified,  (de  Schweinitz,  "Diseases  of  the 
Eye.") 

the  lens  to  which  they  diverge,  when  the  point  of  these 
divergent  rays  is  nearer  to  the  lens  than  its  principal 


THE  PRINCIPLES  OF  VISION  185 

focus.  In  this  case  the  rays  on  the  opposite  side  of  the 
lens,  instead  of  converging,  continue  in  a  divergent 
course. 


Fig.  42.— Virtual  image  of  a  concave  lens:  0\  B'  is  the  virtual  image 
of  the  candle;  0,  B,  erect  and  diminished  in  size,  (de  Schweinitz,  "Dis- 
eases of  the  Eye.") 

The  virtual  image,  seen  through  a  convex  lens,  is 
magnified,  while  that  seen  through  a  concave  lens  is 
reduced. 


Fig.  43-— Image  formed  by  a  convex  lens:  0,  B  is  the  object;  0',  B'  is  the 
inverted  image,     (de  Schweinitz,  "Diseases  of  the  Eye.") 

The  image  formed  by  a  convex  lens  is  inverted.  This 
is  so  with  the  unage  formed  upon  the  retina.  (As  an 
example,  look  at  the  image  on  the  ground-glass  of  a 
camera.)     Following  the  refraction  of  this  image  for- 


1 86  OPHTHALMOLOGY  FOR  VETERINARIANS 

ward,  it  again  becomes  upright.  (As  an  example,  place 
a  lantern-slide,  inverted,  in  a  ''magic  lantern,"  and  the 
picture  is  projected  upright  on  the  screen.) 

Lenses  used  for  the  correction  of  refractive  errors- 
spectacle  lenses — are  the  spheric,  concave  and  convex, 
and  cylindric  lenses.  The  spheric  lenses  are  cut  from 
a  sphere,  that  is,  the  surfaces  have  an  equal  radii  of 
curvature.  Such  lenses  are  called  biconvex  or  bicon- 
cave. Those  with  a  plane  surface  on  one  side  and  a 
curved  surface  on  the  other  are  called  planoconvex 
and  planoconcave  spherics.  Cylindric  lenses  are  cut 
from  a  cylinder,  and  refract  at  right  angles  to  the  axis 
of  the  cylinder.    These  are  also  convex  and  concave. 

Convex  lenses  are  called  plus  (+)  and  concave  lenses 
are  called  minus  (  — ). 

Lenses  are  now  numbered  according  to  their  focal 
length  in  metric  measurements.  A  lens  whose  focal 
length  is  i  meter  is  called  a  i  diopter  lens.  A  lens  of 
2  meters  focal  length,  0.50  diopter;  one  of  |  meter  focal 
length,  2  diopters.  A  meter  equals  in  the  English  system 
39.37  inches. 

A  plus  one  diopter  spheric  lens  is  designated  thus, 
4- i.oo  D.  S.  A  minus  one  diopter  spheric  lens  is  written, 
-1. 00  D.  S.  In  writing  for  plus  or  minus  cylinders, 
the  same  signs  are  used  before  the  number,  but  in  place 
of  the  S.  a  C.  is  used,  and,  following  this,  the  axis  of 
the  cylinder  is  indicated,  thus:  +1.50  D.  C.  Ax.  90°; 
-2.00  D.  C.  Ax.  180°. 


THE  PRINCIPLES  OF  VISION  187 

A  plus  lens  is  neutralized  by  placing  a  minus  lens  of 
equal  ''strength"  before  it.  For  example,  place  a  +1.00 
D.  S.  before  a  —  i.oo  D.  S.  and  it  has  the  effect  of  a  glass 
whose  sides  are  parallel. 

When  the  rays  of  light  enter  the  eye  from  an  object 
at  infinity,  that  is,  from  a  distance  of  20  feet  or  more, 
the  normal  eye  should  be  at  rest,  and  the  object  will  be 
''focused"  or  formed  sharply  upon  the  macula.  The 
image  on  the  retina  is  inverted.  The  rays  cross  at  a 
point  which  is,  approximately,  in  man  15  mm.  anterior 
to  the  retina  and  5  mm.  posterior  to  the  cornea.  This 
is  according  to  a  schematic  eye  devised  by  Bonders. 
(These  distances  would  be  relative  in  animals'  eyes, 
according  to  the  size  of  the  eye.)  An  object  i  meter 
long  vertically,  placed  at  15  meters  distance  from  the 
eye,  would  produce  a  retinal  image  in  vertical  measure- 
ments, I  mm.  The  size  of  the  retinal  image  is  influenced 
by  the  variations  of  the  visual  angle,  and  the  latter  varies 
according  to  the  size  and  distance  of  the  object  from  the 
eye  or  the  optical  center  of  the  lens. 

The  acuity  of  vision  is  the  ability  to  see  objects  of  a 
certain  size  and  at  a  certain  distance  distinctly.  This 
depends  upon  a  normal  visual  apparatus  and  proper 
light.  Under  normal  conditions  the  visual  acuity  of 
animals  of  a  kind  should  be  the  same.  A  bird,  however, 
can  see  a  grain  or  creeping  thing  at  a  much  greater 
distance  than  can  a  cow  or  horse.  They,  therefore, 
have  a  greater  visual  acuity.    Man  can  count  the  bricks 


1 88  OPHTHALMOLOGY  FOR  VETERINARIANS 

of  a  building  when  near  to  it,  but  at  a  distance  he  can 
only  discern  the  outHne  of  the  structure.  It  is  the  nor- 
mal visual  acuity  that  we  seek  to  obtain  in  man  when  we 
correct  the  vision  in  cases  of  refractive  errors.  Fuchs 
says:  ^'We  select  for  the  test  not  one,  but  two  parallel 
lines,  and  then  determine  the  greatest  distance  from  the 
eye  at  which  they  can  still  be  perceived  as  separate  ob- 
jects. From  this  can  readily  be  calculated  the  minimum 
visual  angle,  which,  for  a  normal  eye,  amounts  to 
about  i'."  (Snellen's  test-types  have  been  constructed 
upon  the  basis  of  this  determination,  but  for  whom  this 
work  is  intended — the  veterinarian — it  is  unnecessary 
to  go  further  into  this  particular  subject  or  to  discuss 
the  test-types  and  their  value  in  the  correction  of  the 
refractive  errors  in  man.) 

Eyes  that  are  defective  range  from  nearly  the  normal 
visual  acuity  to  mere  perception  of  light.  These  de- 
fects may  be  due  to  errors  of  refraction  or  diseases  of  the 
retina,  chorioid,  optic  nerve,  cornea,  or  lens.  A  dis- 
turbed nutrition  of  the  eyeball  may  produce  a  torpor  of 
the  retina  which  causes  a  reduction  in  the  visual  acuity, 
particularly  if  the  illumination  is  not  perfect.  In  these 
cases  the  vision  is  greatly  reduced,  proportionately 
after  dark. 

Accommodation. — Should  the  power  to  accommodate 
vision  be  paralyzed,  the  image  of  an  object  w^ithin  the 
distance  known  as  infinity — about  20  feet — would  be 
very  imperfectly  formed  upon  the  retina,  because  the 


THE  PRINCIPLES  OF  VISION  189 

focal  point  would  fall  relatively  behind  the  retina.  To 
produce  acute  vision  for  all  near  objects  it  is  necessary 
to  accommodate  the  vision,  which  is  done  unconsciously. 
For  example,  take  a  tripod  camera,  throw  the  focusing 
cloth  over  your  head,  and  focus  an  object  at  100  feet 
distance  on  the  ground  glass;  now,  without  changing  the 
focusing  apparatus,  view  some  object  at,  say,  10  feet 
distance  from  the  camera,  and  you  v/ill  notice  the  image 
on  the  ground  glass  is  blurred.  Now  rack  the  lens 
forward,  increasing  the  distance  from  the  lens  to  the 
ground  glass,  and  the  real  image  will  appear  sharply 
cut  in  detail.  This  is  called  focusing  the  object.  Ac- 
commodation of  vision  is  practically  the  same  thing, 
except  it  is  done  in  a  different  way  and  by  a  physiologic 
organ  instead  of  a  physical  apparatus.  Accommodation 
is  accomplished  not  by  increasing  the  distance  between 
the  lens  and  the  retina,  but  by  increasing  the  convexity 
of  the  crystalline  lens  sufficiently  to  cause  a  clearly 
defined  retinal  image.  The  ciliary  muscle  is  the  governor 
controlling  the  variations  in  the  convexity  of  the  crystal- 
line lens  for  all  distances  within  20  feet.  When  the 
ciliary  muscle  contracts,  the  zonule  of  Zinn,  which 
supports  the  lens  to  the  muscle,  relaxes,  allowing  the 
lens  in  its  capsule  to  expand  and  become  more  convex 
by  its  own  elasticity.  The  nearer  the  object  to  the  eye 
the  greater  must  be  the  accommodation. 

In  young  subjects  accommodation  is  very  easily  ac- 
compHshed  because  the  lens  is  soft  and  very  readily  re- 


igo  OPHTHALMOLOGY  FOR  VETERINARIANS 

sponds;  but  in  older  subjects  it  loses  its  elastic  qualities 
and  responds  less  readily  to  the  action  of  the  ciliary  mus- 
cle, and  objects  which  could  formerly  be  seen  near  the 
eye  have  to  be  carried  much  farther  away  to  be  seen 
distinctly.  This  is  noticeable  in  man  at  about  forty- 
five  years  of  age,  and  spheric  lenses  have  to  be  placed 
before  the  eyes  to  make  up  the  deficiency.  The  condi- 
tion is  known  as  presbyopia. 

Accommodation  is  usually  determined  between  two 
points,  known  as  the  near  point  (punctum  proximum) 
and  the  far  point  (punctum  remotum).  The  near  point 
is  that  point  nearest  the  eye  at  which  a  certain  object 
can  be  seen  distinctly.  The  far  point  is  the  greatest 
distance  from  the  eye  at  which  the  same  object  can  be 
distinctly  seen.  These  points  vary  with  different  in- 
dividuals, and  especially  so  when  errors  of  refraction 
exist. 

The  hyperopic  eye  will  necessarily  have  to  accommo- 
date proportionately  more  than  normal,  and  the  myopic 
eye  less  so  or  not  at  all.  This  is  because,  in  the  first 
instance,  the  focus  is  back  of  the  retina  when  the. ac- 
commodation is  at  rest;  and,  in  the  second  instance,  it 
is  anterior  to  the  retina.  In  hyperopic  eyes  the  ciliary 
muscle  is  overdeveloped,  while  in  myopic  eyes  it  is  often 
atrophied  from  non-use. 

During  accommodation  the  eyes  converge  propor- 
tionately to  the  distance,  and  the  pupil  is  diminished  in 
size,  reflexly.    The  pupil  is  dilated  when  the  muscle  of 


THE  PRINCIPLES  OF  VISION  191 

accommodation  is  paralyzed.  Paralysis  of  the  ac- 
commodation is  often  caused  by  contusion  of  the  eye- 
ball, influenza,  diabetes,  and  diseases  of  the  central 
nervous  system.  Diphtheria  is  a  common  cause  in  man. 
Belladonna  and  its  alkaloids  will  produce  it  tem- 
porarily. Spasm  of  the  accommodation  often  occurs, 
and  when  an  eye  is  hyperopic  it  becomes  falsely  myopic. 
It  is  partly  for  this  reason  that  a  cycloplegic  should  be 
used  when  the  eyes  are  being  tested  for  refractive  errors. 
The  retina  is  the  receptive  coat  of  the  eye  (as  the  dry 
plate  receives  the  image  in  the  camera),  and  the  direct 
image  received  by  the  retina  falls  upon  the  ^'macula 
lutea,"  which  is  in  the  direct  visual  axis.  The  retina  is 
composed  of  nerve-elements  intimately  associated  with 
the  optic  nerve-fibers.  These  nerve-elements,  the  so- 
called  rods  and  cones — particularly  the  latter,  of  which 
the  macula  is  principally  composed — are  exceedingly 
sensitive  to  the  vibration  of  light  rays.  The  image  is 
produced  by  the  vibration  of  these  Hght  rays  refracted 
or  focused  upon  the  macula,  which  is  transmitted  to  the 
optic  nerve-fibers,  thence  to  the  center  of  vision  in  the 
occipital  lobes  of  the  brain.  If  the  image  falls  upon  the 
same  center  of  each  eye,  two  images  are  naturally  pro- 
duced, which  become  one  in  the  visual  center,  just  as 
two  pictures  are  fused  into  one  while  looking  through 
the  spheroprisms  of  a  stereoscope.  Double  vision  (dip- 
lopia) is  experienced  when  one  or  more  of  the  extrinsic 
muscles  are  paralyzed. 


192 


ophthal:\iology  for  veterinarians 


Fields. — When  the  eyes  are  fixed  upon  some  object 
directly  in  front  of  them,  objects  at  the  left  are  noticed 
by  the  right  half  of  the  retina  of  each  eye,  while  those  at 
the  right  are  noticed  by  the  left  half  of  the  retina  of  each 
eye;  those  above  by  the  lower  half,  and  those  below  by 


Fig.  44. — Diagram  illustrating  the  visual  path  and  its  relation  to  the 
visual  field,  left  lateral  hemianopsia  being  shown  (Seguin). 

the  upper  half.  These  are  called  the  fields  of  vision,  and 
they  vary  greatly  in  animals  of  different  kinds.  They 
are  influenced  by  the  position  of  the  eyeballs,  the  promi- 
nence of  the  orbital  ridges,  the  distance  between  the 
eyes,  and  the  structure  of  the  face.  In  man,  because  of 
his  requirements,  the  fields  are  probably  greater  than  in 


THE  PRINCIPLES  OF  VISION  193 

other  animals.  The  horizontal  field  is  half  of  a  circle, 
180  degrees,  while  the  upper  and  lower  fields  are  some- 
what less  because  of  the  supra-orbital  ridges  and  the 
cheek  bones.  The  inner  field  of  each  eye,  separately, 
is  less  because  of  the  nose. 

In  the  lower  vertebrates  complete  decussation  of  the 
optic  nerves  takes  place,  but  in  animals  of  the  higher 
order  a  partial  decussation,  or  crossing  over  of  the  inner 
portion  of  the  optic  nerves,  takes  place  at  the  chiasm. 
This  causes  the  image  of  objects  seen  from  the  left  field 
to  be  conveyed  to  the  right  visual  center,  and  those  from 
the  right  field  to  the  left  visual  center.  It  very  often 
happens  that  an  animal  cannot  see  beyond  the  median 
line,  either  to  the  right  or  to  the  left.  This  is  known  as 
homonymous  hemianopia  (right  and  left,  respectively). 
Right  homonymous  hemianopia  is  due  to  some  defect 
of  the  optic  nerves,  tracts,  or  visual  center  supplying 
the  left  half  of  each  retina.  Left  homonymous  hemian- 
opia is  due  to  some  defect  in  the  optic  nerves,  tracts,  or 
visual  center  supplying  the  right  half  of  each  retina. 
When  both  outer  fields  are  obhterated  it  is  known  as 
bitemporal  hemianopia,  and  is  due  to  some  defect  of  the 
inner  half  of  each  retina  or  its  optic  nerve  supply. 
When  the  inner  fields  are  obHterated  (binasal  hemianopia) 
the  outer  half  of  each  retina  is  involved. 

W^hen  hemianopia  occurs  in  both  eyes,  as  it  most  al- 
ways does,  it  is  due  to  pressure  or  disease  of  the  optic 
tracts  or  visual  center.    Reaction  of  the  pupil  to  light, 

13 


194  OPHTHALMOLOGY  FOR  VETERINARIANS 

when  the  normal  half  of  the  retina  is  shaded,  determines 
the  location  of  the  pressure  or  disease.  The  pupil  fails 
to  react  to  light  when  pressure  is  anterior  to  the  so-called 
* 'reflex  arc/'  that  is,  anterior  to  the  origin  of  the  third 
nerve. 

The  fields  of  vision  are  greatly  contracted  in  glaucoma 
and  in  diseases  of  the  optic  nerve  and  retina,  but  in  a 
work  of  this  nature  it  is  unnecessary  to  go  into  such 
details. 

Scotoma. — A  portion  of  the  field  of  an  eye  may  be 
wiped  out  by  reason  of  disease  or  atrophy  of  that  portion 
of  the  retina  which  should  receive  it.  Such  a  condition 
is  known  as  a  scotoma.  For  instance,  a  hemorrhage 
may  occur  in  the  macula  which  will  produce  a  central 
scotoma;  that  is,  the  object  in  the  direct  visual  axis 
cannot  be  seen,  while  the  other  fields  are  preserved.  If 
the  macula  is  normal,  but  disease  and  atrophy  occur 
in  some  other  portion  of  the  retina,  the  central  field  will 
be  preserved,  but  that  portion  of  the  field  which  is 
received  by  the  diseased  portion  of  the  retina  will  be 
obhterated. 


CHAPTER  XX 

ERRORS  OF  REFRACTION 

There  is  no  doubt  that  some  animals  have  refractive 
errors  as  well  as  man,  but,  as  the  requirements  of  vision 
are  so  vastly  different  from  those  of  man,  it  will  probably 
be  a  long  time,  if  ever,  when  these  errors  will  be  corrected 
by  the  use  of  lenses.  However,  it  may  be  well  to  give  the 
veterinary  student  some  knowledge  of  refractive  errors 
at  this  time. 

There  are  four  principal  errors — viz.:  •  Hyperopia 
(farsightedness),  myopia  (nearsightedness),  astigmatism 
(where  one  meridian  is  either  hyperopic  or  myopic),  and 
presbyopia  (the  natural  failing  vision  of  age). 

Hyperopia  is  nearly  always  congenital,  and  is  due  to  a 
short  eyeball  from  before  backward,  so  that  the  focus 
falls  behind  the  retina.  By  some  effort  of  the  ciUary 
muscle  the  focus  is  brought  forward  to  the  retina.  In 
some  cases,  by  gradual  development,  the  eye  becomes 
normal  in  its  anteroposterior  measurements,  though  in 
many  cases  hyperopia  exists  throughout  life.  A  plus 
(convex)  spheric  lens  is  necessary  to  correct  this  con- 
dition. 

Myopia  is  just  the  opposite  of  hyperopia;  that  is,  the 
eyeball  is  longer  from  before  backward  than  normal, 

195 


196  OPHTHALMOLOGY  FOR  VETERINARL\NS 

and  the  focus  of  distant  objects  falls  in  front  of  the 
retina;  consequently,  vision  is  blurred  or  imperfect,  and 
should  the  ciUary  muscle  contract  in  this  case  it  would 
only  increase  the  myopia.  For  all  near  objects,  however, 
Httle  or  no  accommodation  is  required.  Myopia  is 
nearly  always  congenital,  though  in  some  cases  it  is 
acquired.  A  minus  (concave)  spheric  lens  is  used  to 
correct  this  error. 

Astigmatism  may  be  simple,  compound,  or  mixed.  A 
simple  astigmatism  is  one  in  which  the  eye  is  hyperopic 
or  myopic  in  one  meridian  only.  It  is  known  as  regular 
astigmatism  when  vertical  or  horizontal  and  irregular 
when  it  deviates  from  these  directions.  A  compound 
astigmatism  is  one  in  which  the  eye  is  hyperopic  or 
myopic  combined  with  an  astigmatism  of  that  t>^e. 
Mixed  astigmatism  is  one  which  is  hyperopic  in  one 
meridian  and  myopic  in  the  opposite  meridian. 

Astigmatism  is  due  to  an  irregularity  in  the  curva- 
ture or  refraction  of  the  cornea,  the  lens,  or  both.  It 
may  be  congenital,  but  is  more  often  acquired.  It  often 
follows  operations  or  disease  of  the  cornea.  Simple 
astigmatism  is  corrected  with  a  plus  or  minus  cyHndric 
lens,  as  the  case  may  be.  Compound  astigmatism  is  cor- 
rected with  a  plus  or  minus  spheric  lens,  combined  with 
a  plus  or  minus  cyHndric  lens,  as  the  case  may  be 
compound  hyperopic  or  compound  myopic.  Mixed 
astigmatism  is  corrected  with  a  plus  spheric  and  minus 
cylinder  or  a  minus  spheric  and  a  plus  cylinder. 


ERRORS  OF   REFRACTION  197 

Presbyopia  is  a  gradual  failure  of  the  accommodation 
for  near  work.  Man  becomes  presbyopic  between  forty 
and  fifty  years  of  age.  It  is  due  to  a  gradual  hardening 
of  the  lens,  which  fails  to  respond  to  the  action  of  the 
ciliary  muscle.  This  error  is  corrected  by  placing  before 
the  eye  a  plus  spheric  lens. 

Emmetropia. — An  emmetropic  eye  is  one  that  is 
normal  as  far  as  any  refractive  error  is  concerned. 
The  focus  of  all  distant  objects  fall  upon  the  retina  with- 
out any  effort  of  the  cihary  muscle. 

Major-General  F.  Smith  has  examined  100  horses' 
eyes,  and  found  that  only  i  per  cent,  were  emmetropic, 
3  per  cent,  were  hyperopic,  6  per  cent,  had  mixed 
astigmatism,  and  90  per  cent,  were  myopic. 

It  is  no  doubt  due  to  this  fact  that  so  many  horses  shy, 
as  distant  objects  are  not  clear  until  they  come  suddenly 
upon  them.  Dogs  and  cats  were  formerly  thought  to  be 
hyperopic,  but  recent  investigators  have  found  them  to 
be  myopic.  A  large  number  of  wild  animals'  eyes  have 
been  examined  and  have  been  found  to  be  hyperopic. 

Method  Used  to  Determine  the  Refractive  Error.— 
For  diagnostic  purposes  retinoscopy  may  be  used. 
The  retinoscope  is  a  small,  circular,  plane  mirror  with  a 
small  hole  in  the  center.  A  Kght  is  placed  near  the  right 
side  of  the  head,  shading  the  eyes,  and  a  reflection  of  this 
light  is  thrown,  at  one  meter's  distance,  into  the  pupil 
through  the  refractive  media  to  the  retina.  The  exam- 
iner looks  through  the  central  opening,  and  moves  the 


198  OPHTHALMOLOGY  FOR  VETERINARIANS 

mirror  vertically  and  horizontally.  If  the  reflection  cast 
upon  the  retina  moves  in  the  same  direction  as  the 
movement  of  the  mirror,  the  animal  is  hyperopic.  If 
the  reflection  moves  in  the  opposite  direction  from  that  of 
the  mirror,  the  animal  is  myopic.  If  the  reflection  moves 
with  in  one  meridian  and  against  in  the  other,  mixed 
astigmatism  is  present.  If  it  moves  with  in  one  meridian 
and  not  at  ah  in  the  opposite  meridian,  astigmatism  is 
present.  If  it  moves  against  in  one  meridian  and  not 
at  all  in  the  opposite  meridian,  astigmatism  is  also 
present.  In  man,  the  correction  is  made  by  placing 
lenses,  either  plus  or  minus,  before  the  eye  until  one  is 
found  that  will  neutralize  the  movement  of  the  reflec- 
tion. When  the  movement  is  with,  plus  lenses  are  used; 
and  when  it  is.  against,  minus  lenses  are  used.  Com- 
pound errors  are  determined  when  the  movement  of  the 
same  character  is  greater  in  one  meridian  than  in  the 
opposite  meridian. 

In  order  to  get  a  perfect  correction  one  must  control 
the  action  of  the  ciliary  muscle  by  the  use  of  a  cyclo- 
plegic.  Atropin  in  i  per  cent,  solution  or  homatropin  in 
2  per  cent,  solution  may  be  used.  The  former  may  be 
used  three  times  a  day  for  a  few  days  before  examina- 
tion, while  the  latter  has  its  maximum  effect  in  about  an 
hour's  time.  It  will  be  necessary  to  drop  this  into  the 
eye  every  ten  minutes  for  an  hour  at  least.  The  effect 
of  this  gradually  wears  away,  so  that  the  animal  can 
accommodate  its  vision  in  twenty-four  to  forty-eight 


ERRORS  OF  REFRACTION  199 

hours;  while,  if  atropin  is  used,  the  effect  will  last  several 
days. 

To  do  good  work  requires  a  great  deal  of  time,  ex- 
perience, and  patience.  In  man,  the  subjective  method  of 
examination  usually  follows  retinoscopy,  as  the  patient 
will  not  always  accept  his  full  correction.  By  the  sub- 
jective method  is  meant  placing  the  patient  at  a  distance 
of  20  feet  from  the  Snellen  test-types,  and  requiring  him 
to  read  the  normal  line  for  that  distance,  either  with  the 
exact  correction  by  the  retinoscope  test  or  by  a  modifica- 
tion of  that  correction. 

Of  course,  it  is  unnecessary  to  state  that,  with  the  Hght 
near  the  head  of  the  animal,  it  will  be  necessary  to  have 
the  animal  in  a  darkened  room.  With  much  experience 
one  can  become  quite  proficient  with  the  use  of  the 
retinoscope. 


CHAPTER  XXI 

MEDICINES  USED   IN  OPHTHALMIC  THERAPEUTICS 

There  is  a  great  variety  of  medicines  used  in  the 
treatment  of  diseases  of  the  eye,  but  it  is  better  to  become 
familiar  with  the  action  of  a  few  remedies  and  to  know 
when  to  use  them. 

Antiseptic  Washes: 

Normal  salt  solution  is  a  j  of  i  per  cent,  solution  of  common  salt.  This 
makes  an  excellent  cleansing  agent  in  mild  cases,  and  is  safe  to  use. 

Boric  acid  in  saturated  solution.  A  feebly  antiseptic  and  safe  wash 
to  use. 

Corrosive  sublimate  in  from  i  :  5000  to  i  :  2000  solutions.  This  is 
more  antiseptic,  but  also  more  apt  to  be  followed  by  reaction  when 
strong  solutions  are  used. 

Nitrate  of  silver  in  2  per  cent,  solution.  It  is  better  to  apply  this 
with  a  swab  of  cotton  or  a  camel's  hair  brush.  It  is  converted 
into  chlorid  of  silver  when  it  comes  in  contact  with  the  tears,  and 
should  be  immediately  washed  off  with  sterile  water. 

Argyrol,  one  of  the  albumose  of  silver  salts,  used  in  solutions  of  from 
10  to  50  per  cent.  The  strong  solutions  should  be  used  only  in 
extreme  cases  of  purulent  inflammation.  Each  manufacturer  has 
a  name  for  his  special  preparation — ^protargol,  argentamin,  argonin, 
etc. — which  contain  different  amounts  of  silver. 

Astringents: 

Sulphate  of  zinc  in  |  to  |  of  i  per  cent,  solution. 

Sulphate  of  copper. 

Alum.     The  two  last  are  usually  used  in  the  crystal  form,  rubbed  on 

the  everted  conjunctiva,  and  immediately  washed  off. 
Tannate  of  glycerin,  U.  S.  P. 
200 


MEDICINES  USED  IN  OPHTHALMIC  THERAPEUTICS     20l 

Local  Anesthetics: 

Cocain  hydrochlorid  in  2  to  10  per  cent,  solutions. 
Holocain,  i  per  cent,  solution. 

The  first  also  dilates  the  pupil.  The  last  is  feebly  antiseptic  and 
does  not  dilate  the  pupil. 

Caustics: 

Silver  nitrate  stick  is  used  to  touch  ulcerated  portions  of  the  lid.  It 
is  not  used  on  the  globe  except  to  stimulate  the  edges  of  an  open 
wound. 

Tincture  of  iodin  should  never  be  dropped  into  the  eye,  but  it  is  valuable 
to  apply  to  sloughing  ulcers  of  the  cornea  or  lids,  from  the  point  of 
a  pencil  of  cotton. 

Carbolic  acid  is  used  in  cases  in  which  the  tincture  of  iodin  is  indi- 
cated, and  in  the  same  way. 

The  actual  cautery.  This  may  be  used  in  the  form  of  an  electric 
cautery,  or  a  fine  platinum  wire  may  be  heated  in  an  alcohol  flame. 
It  is  used  in  cases  of  sloughing  ulcer  of  the  cornea  and  in  one  about 
to  perforate.     Great  care  must  be  exercised  in  its  use. 

Agents  Affecting  the  Size  of  the  Pupil: 
Mydriatics  dilate  the  pupil. 

Atropin  sulphate,  i  per  cent,  solution. 
Homatropin  hydrobromid,  2  per  cent,  solution. 
Hyoscyamin  hydrobromid,  i  per  cent,  solution. 
Duboisin  sulphate,  i  per  cent,  solution. 
Scopolamin,  |  to  i  per  cent,  solution. 

The  first  two  are  the  more  reliable.  They  paralyze  the  accommo- 
dation (cycloplegia)  as  well  as  dilate  the  pupil  (mydriasis). 
The  first  has  a  more  lasting  effect,  and  should  be  used  in  cases 
of  iritis,  injuries,  and  ulcers  of  the  cornea.  The  second  is  used 
more  for  temporary  effect  for  the  examination  of  the  fundus,  etc. 
Myotics  contract  the  pupil. 

Pilocarpin  hydrochlorid,  i  to  2  per  cent. 
Eserin  sulphate,  \  to  i  per  cent,  solution. 

Lymphagogiies: 

Dionin,  5  to  10  per  cent,  solutions. 

Redness  and  edema  of  the  conjunctiva  often  follow  the  initial  use 
of  dionin,  which  soon  subsides.  In  severe  cases  of  iritis  and 
glaucoma  the  powder  is  often  used  in  place  of  the  solution. 


202  OPHTHALMOLOGY  FOR  VETERINARIANS 

Hemostatics: 

The  extracts  of  the  suprarenal  gland  of  the  sheep.  There  are  numerous 
preparations  of  this  in  solution,  such  as  adrenahn  chlorid,  adrin. 
etc.  They  are  used  in  operations  to  lessen  hemorrhage.  In  opera- 
tions on  the  hds  they  should  be  injected  hypodermically. 

Ointments: 

Yellow  oxid  of  mercury,  i  to  2  per  cent. 

Red  iodid  of  mercury,  3  of  i  per  cent. 

Iodoform,  10  to  20  per  cent. 

Aristol,  10  to  20  per  cent. 

Oxid  of  zinc,  U.  S.  P. 

Ichthyol,  5  to  20  per  cent. 

The  first  four  are  used  as  indicated,  in  keratitis  and  ulcer  of  the 
cornea.  The  two  last  are  used  in  diseases  of  the  skin  about  the 
lids.     Equal  parts  of  vaselin  and  lanolin  are  used  as  a  base. 

Powders: 
Boric  acid. 

Finely  powdered  iodoform. 
Calomel. 
The  first  two  are  often  mixed  in  equal  parts  and  used  as  a  dusting- 
powder  following  operations  on  the  lids.     They  are  of  great  value 
in  purulent  ulcers  of  the  cornea. 

Comhinations: 

When  two  or  more  of  these  medicines  are  indicated,  they  may  be  mixed, 
if  not  incompatible;  for  instance,  atropin  or  pilocarpin  may  be 
mixed  with  an  ointment  or  with  a  collyrium,  etc.  It  is  better  to  treat 
each  case  according  to  its  requirements  and  not  have  too  many 
"set"  formulae. 

More  accurate  percentage  solutions  can  be  made  by  using  the  Metric 
System. 


INDEX 


Abrasions  of  cornea,  i66 
Abscess  of  lid,  42 

treatment  of,  42 
Accessory  eyelid,  27 
Accidents  attending  extraction  of 

cataract,  149 
Accommodation,  180,  189,  190 

muscle  of,  25 

paralysis  of,  191 

spasm  of,  191 
Acuity  of  vision,  187 
Albinos,  24 
Amblyopia,  toxTc,  134 

treatment,  135 
Anatomy  of  eye,  11 
Anemia  of  retina,  127 
Anesthetics,  local,  201 
Aniridia,  iii 
Ankyloblepharon,  ^8 

operation  for,  55,  56 
Antiseptic  washes  for  eye,  200 
Aqueous  humor,  21 

turbid,  30 
Artery,  hyaloid,  26,  27 
Artificial  eye,  172 
Astigmatism,  80,  196 

compound,  196 

mixed,  196 
Astringents,  200 
Atrophy  of  optic  nerve,  135,  175 

of  retina,  129,  130 

Blepharitis,  67 
marginalis,  38,  72 


Blepharitis    marginalis,    treatment 

of,  39 
Blepharospasm,  38,  89 
Blindness,  moon,  155 
Bowman's  membrane,  20,  30,  88,  97 
Bulbar  portion  of  conjunctiva,  27 
Buphthalmus,  105 
Burns  of  conjunctiva  and  cornea,  83 

of  lid,  35 

Canal  of  Petit,  26 
Canthoplasty,  54,  99 
Canthotomy,  98 
Capsular  cataract,  140,  141 
Capsule  of  lens,  14,  25,  26 

Tenon's,  12,  61 
Carcinoma  of  lid,  42 
Caruncle,  27 
Cataract,  31,  137,  157 
capsular,  140,  141 
discission  of,  144 
extraction  of,  145 

accidents  attending,  149 
dressings  following,  151,  152 
operations  for,  144 
posterior  polar,  3,  138 
senile,  139 
traumatic,  138 
Cataracts,  classification  of,  137 
Catarrhal  conjunctivitis,  acute,  64 
causes,  65 
diagnosis,  65 
treatment,  66 
Caustics,  201 

203 


204 


INDEX 


Chalazion,  30,  40 

treatment  of,  41 
Chamber,  anterior,  21,  22 
exudations  in,  31,  113 
posterior,  21 
Chambers  of  eye,  14 
Chemosis,  30 
Choked  disk,  134 
Chorea,  38 
Chorioid,  15,  25,  131 
diseases  of,  130 
function  of,  16 
layers  of,  16,  17 
pigment  of,  15,  16,  17 
Chorioiditis,  131,  170 

purulent,  132 
CiHary  body,  24 
diseases  of,  no 
tumors  of,  121,  122 
muscle,  25 
processes,  26 
region,  wounds  of,  115 
vessels,  15 
Coats  of  eye,  14 
Coloboma  of  iris,  in 
Compound  astigmatisn},  196 
Concave  lenses,  186 
Congenital  pupil,  in 
Conjugate  foci,  183 
Conjunctiva,  15,  27,  30,  33,  34, 
80,  83,  88,  146 
bulbar  portion,  27 
bums  of,  83 
chemosis  of,  30 
diseases  of,  64 
foreign  bodies  in,  80 

treatment,  81 
palpebral,  27,  72,  79 
tuberculosis  of,  79 
tumors  of,  84-86 
xerosis  of,  75 
Conjunctivitis,  64,  86 


75; 


Conjunctivitis,  acute  catarrhal,  64 
causes  of,  65 
diagnosis  of,  65 
treatment  of,  66 
chronic,  66 

treatment  of,  68 
folUcular,  74 
membranous,  76 
phlyctenular,  71 
purulent,  30,  68 
symptoms  of,  68 
treatment  of,  69 
Contusions,  162 
Convex  lenses,  186 
Cornea,  20,  30,  43,  66,  79-81,  83, 
160 
abrasions  of,  166 
burns  of,  83 
diseases  of,  88 
epithehoma  of,  20,  21 
foreign  bodies  in,  80 

treatment,  81 
herpes  of,  99 
layers  of,  20 
opacities  of,  106 

treatment  of,  107 
perforating  wounds  of,  166 
staphyloma  of,  102,  103 
ulcers  of,  71,  82,  90-93 
causes,  91 
treatment,  93 
xerosis  of,  102 
Corpora  nigra,  23 
Cowpox,  42,  71,  91 
Crystalline  lens,  25,  31,  67 
capsule  of,  14,  25,  26 
construction  of,  25 
diseases  of,  137 
luxation  of,  142 
nucleus  of,  26 
opacity  of,  31 
shape  of,  25 


INDEX 


205 


Cyclitis,  30,  114,  151,  156,  170 

treatment  of,  116,  117 
Cylindric  lenses,  186 
Cysts  of  iris,  119 

Dacryocystitis,  57 

Decreased  tension,  32 

Dendritic  keratitis,  100 

Descemet's  membrane,  20,  21 

Desiccation  keratitis,  loi 

Detachment  of  retina,  27,  128 

Dilator  pupillae  muscle,  23 

Diphtheria  in  fowls,  76,  77 

Diplopia,  80,  191 

Discission  of  cataract,  144 

Disk,  choked,  134 
optic,  14 

Dislocation     of    crystalline     lens, 
142 

Distichiasis,  44 

Dressings  after  extraction  of  cat- 
aract, 151,  152 

Duct,  meibomian,  30 
stenosis  of,  58 

EccHYMOSis  of  lids,  35 
Ectopia  pupillae,  iii 
Ectropion,  36 

operations  for,  46-50 
Edema  of  lids,  35 

of  nictitans  membrane,  87 

of  retina,  127 
Elephantiasis  of  lids,  37 
Emphysema  of  Hds,  35 
Enucleation,  118,  170,  171 
Enzootic  ophthalmia,  69 
Epiphora,  29,  36,  57 
Episcleral  tissue,  15,  27 
Epithelioma  of  cornea,  20,  21 
Errors  of  refraction,  195 

methods    used    to    determine, 
197 


E version  of  lids,  36 

Examination,   systematic,   of    eye, 

29 
Exenteration,  175 
Exophthalmus,  91 
Extraction  of  cataract,  145 
accidents  attending,  149 
dressings  following,  151,  152 
Eye,  anatomy  of,  11 

antiseptic  washes  for,  200 

artificial,  172 

chambers  of,  14 

coats  of,  14 

foreign  bodies  in,  168 

haw  of,  28 

internal  structure  of,  14 

systematic  examination  of,  29 
Eyeball,  muscles  of,  59 

prolapse  of,  172 
Eyelid,  34 

accessory,  27 

third,  12 

tumors  of,  41 

Fetal  hfe,  pupil  in,  24 
Fields  of  vision,  192 
Filamentous  keratitis,  100 
Fluid,  vitreous,  27,  32 
Foci,  conjugate,  183 
Focus,  principal,  182 

virtual,  184 
Follicular  conjunctivitis,  74 
Foramen,  optic,  14,  61 
Foreign  bodies  in  conjunctiva  and 
cornea,  80 
treatment  of,  81 
in  eye,  168 
Fornix  conjunctivae,  34 
Fossa  petellaris,  25 
Fovea  centralis,  18,  20 
Fracture  of  orbit,  174 
Fundus,  reflex,  17,  24 


206 


INDEX 


Gland  of  Harder,  28 
Glands,  meibomian,  2,2)i  37^  4° 

mucous,  34 
Glaucoma,  30,  32,   115,   15 7-1 59 
Glioma,  130 
Globe,  injuries  of,  162 
complications  in,  165 
treatment  of,  166 
with  foreign  bodies  remaining 
in  eye,  168 
lacerations  of,  164,  165 
punctures  of,  163,  164 
Grafts,  Thiersch,  49 
Grape-kernels,  24 

Harder,  gland  of,  28 
Haw  of  eye,  28 
Hemianopia,  195 
Hemorrhage  in  retina,  128 
Herpes  of  cornea,  99 

zoster,  99 
Hordeolum,  40 
Humor,  aqueous,  21 
Hyaloid  artery,  26,  27 

membrane,  14,  26 
Hydrophthalmus,  105 
Hyperemia  of  retina,  128 
Hyperopia,  195 
Hyphemia,  113 
Hypopyon,  89,  92,  93 

Image,  virtual,  183 

Increased  tension,  32,  158 

Inflammation    of    nictitans    mem- 
brane, 86 
sympathetic,  116 

Influenza,  91 

Injuries  of  globe,  162 

complications  in,  165 
treatment  of,  166 
with  foreign  bodies  remaining 
in  eye,  168 


Interstitial  keratitis,  108,  109 
Inversion  of  lids,  36 
Iridectomy,  118,  148 
Iridochorioiditis,  131 
Iridocyclitis,  92,  114,  157 
Iridodialysis,  162 
Iridodonesis,  21 
Iris,  21,  22,  25,  31 

colomba  of,  iii 

cysts  of,  119 

diseases  of,  no 

pigment  of,  22-24 

prolapse  of,  150 

tremulous,  21,  31 

tuberculosis  of,  120 

tumors  of,  119,  121,  122 
Iritis,  92,  112,  114,  145,  151,  156, 
170 

secondary,  115 

symptoms  of,  114 

treatment  of,  11 6-1 18 

Keratectasia,  105 
Keratiris,  36,  88,  90 

dendritic,  100 

desiccation,  loi 

filamentous,  100 

interstitial,  108,  109 

neuroparalytic,  loi 

phlyctenular,  71,  99 

symptoms  of,  89 
Keratoconus,  105 
Keratoglobus,  105 
Keratomalacia,  102 

Lacerations  of  globe,  164,  165 
Lacrimal  apparatus,  diseases  of,  57 

sac,  34 
Lagophthalmus,  37,  91 
Lamina  cribrosa,  15 
Lashes,  2>Z,  39 

in  dog  and  pig,  33 


INDEX 


207 


Layers  of  chorioid,  16,  17 

of  cornea,  20 

of  retina,  18 
Lens,  crystalline,  25,  31,  67 
capsule  of,  14,  25,  26 
construction  of,  25 
diseases  of,  137 
luxation  of,  142 
nucleus  of,  26 
opacity  of,  31 
shape  of,  25 
Lenses,  186 

concave,  186 

convex,  186 

cylindric,  186 

spheric,  182,  186 
Lenticonus,  145 

Levator  palpebrarum,  29,  ^2,  37 
Lids,  39,  71 

abscess  of,  42 
treatment,  42 

burns  of,  35 

carcinoma  of,  42 

diseases  of,  7,^ 

ecchymosis  of,  35 

edema  of,  35 

elephantiasis  of,  37 

emphysema  of,  35 

eversion  of,  36 

in  trichinosis,  30 

inversion  of,  36 

operations  on,  45 

sarcoma  of,  42 

tuberculosis  of,  37 

tumors  of,  41 

ulcers  of,  42 

wounds  of,  36 
Ligament,  palpebral,  S3 

suspensory,  26 

tarsal,  35 
Ligamentum  pectinatum,  22 
Lupus,  42 


Luxation  of  crystalline  lens,  142 
LymphagOgues,  ocular,  201 

Macula  lutea,  18 
Meibomian  duct,  30 

stenosis  of,  58 
glands,  33,  37,  40 
Membrana  nictitans,  12,  27,  81 

action  of,  28 

edema  of,  87 

in  tetanus,  87 

inflammation  of,  86 
pupillaris,  24 
Membrane,  Bowman's,  20,  30,  81 

97 

Descemet's,  20,  21 

hyaloid,  14,  26 
Membranous  conjunctivitis,  76 
Mixed  astigmatism,  196 
Moon  blindness,  155 
Mucous  glands,  34 
Muscle,  ciliary,  25 

dilator  pupillae,  23 

of  accommodation,  25 

retractor,  12,  61 

sphincter  pupillae,  23 
Muscles,  action  of,  61 

affections  of,  61 

extrinsic,  14 

intrinsic,  25 

nerve  supply  of,  61 

oblique,  14,  59,  61 

of  eyeball,  59 

recti,  14,  59 
Mydriasis,  iii 
Mydriatics,  201 
Myopia,  195 
Myosis,  III 
Myotics,  201 

Nerve,  optic,  14 

atrophy  of,  135,  i75 


2o8 


INDEX 


Nerve,  optic,  diseases  of,  133 

sheath  of,  14,  61 
supply  of  muscles,  61 
Neuritis,  retrobulbar,  134 
Neuroparalytic  keratitis,  loi 
Neuroretinitis,  133 
Nictitans  membrane,  12,  27,  81 

action  of,  28 

edema  of,  87 

in  tetanus,  87 

inflammation  of,  86 

Occluded  pupil,  114 
Ointments,  202 
Opacities  of  cornea,  106 
Opacity  of  crystalline  lens,  31 
Ophthalmia,  enzootic,  69 
periodic,  155 
recurrent,  116,  155 

symptoms  of,  156 
Ophthalmoplegia,  62 
Ophthalmoscope,  20,  124,  125,  168 
Optic  disk,  14 
foramen,  14,  61 
nerve,  14 

atrophy  of,  135,  175 

diseases  of,  133 

sheath  of,  14,  61 
Ora  serrata,  16,  18,  20,  26 
Orbicularis  palpebrarum,  29,  33 
Orbit,  fracture  of,  174 
Ox  eye,  105 

Palpebra,  levator,  29,  33,  37 
Palpebral  conjunctiva,  27,  72,  79 

ligament,  ^z 
Pannus,  73,  97,  98 
Panophthalmitis,  118,  132 
PapilUtis,  133 
Paracentesis,  118 
Paralysis  of  accommodation,  191 
Parasites  of  eye,  176,  178 


Parasites  of  eyelids,  176 
Perforating  wounds  of  cornea,  166 
Periodic  ophthalmia,  155 
Petit,  canal  of,  26 
Phlyctenular  conjunctivitis,  71 

keratitis,  71,  99 
Photophobia,  71 
Phthisis  bulbi,  163 
Pigment  of  chorioid,  15-17 
of  iris,  22-24 
of  retina,  19 
of  sclera,  15 
Pinguecula,  78,  79 
Plica  semilunaris,  27 
Posterior  polar  cataract,  138 
Powders,  202 
Presbyopia,  190 
Principles  of  vision,  181 
Prolapse  of  eyeball,  172 

of  iris,  150 
Pterygium,  79 
Ptosis,  37,  62 

operation  for,  56 
Puncta  lacrimalia,  29,  34 
Punctum  proximum,  190 

remotum,  190 
Punctures  of  globe,  163,  164 
Pupil,  24,  30,  153,  160,  190,  194 
congenital,  iii 
in  fetal  life,  24 
occluded,  114 
size  and  shape  of,  in 
Pupillary  membrane,  persistent,  24. 

Ill 

Purulent  chorioiditis,  132 

conjunctivitis,  30,  68 

symptoms  of,  68 

treatment  of,  69 


Recti  muscles,  14,  59 
Recurrent  ophthalmia,  116, 
symptoms  of,  156 


155 


INDEX 


209 


Refraction,  181 

errors  of,  195 

methods    used    to    determine, 
197 
Retina,  17 

and  chorioid,  diseases  of,  124 

anemia  of,  127 

atrophy  of,  129,  130 

detachment  of,  27,  128 

edema  of,  127 

examination  of,  124-127 

function  of,  18 

glioma  of,  130 

hemorrhage  in,  128 

hyperemia  of,  128 

layers  of,  18 

pigment  of,  19 

rods  and  cones  of,  19 

vessels  of,  20 
Retinitis,  128 
Retinoscope,  197,  198 
Retractor  muscle,  12,  61 
Retrobulbar  neuritis,  134 
Rods  and  cones  of  retina,  19 
Roup,  76 

Saemisch  operation,  96,  97 
Sarcoma  of  lid,  42 
Sclera,  14,  167 

pigment  of,  15 
Scotoma,  131,  194 
Senile  cataract,  139 
Sheath' of  optic  nerve,  14,  61 
Sheep-pox,  71 
Soot-balls,  24 
Space,  circumlental,  25 
Spasm  of  accommodation,  191 
Spheric  lenses,  182,  186 
Sphincter  pupillas  muscle,  23 
Staphyloma  of  cornea,  102,  103 
Stenosis  of  meibomian  duct,  58 
Sty,  40 

14 


Suspensory  ligament,  26 

Symblepharon,  84 

Sympathetic  inflammation,  116 

Synechiae,  114 

Systematic  examination  of  eye,  29 

Tapetum  lucidum,  17 

Tarsal  ligament,  33 

Tarsitis,  37 

Tarsus,  33,  74 

Tenonitis,  30 

Tenon's  capsule,  12,  61 

Tension,  32,  114,  158,  159 

decreased,  32 

increased,  32,  158 
Tetanus,  28 

nictitans  membrane  in,  87 
Therapeutics,  ocular,  200 
Thiersch  grafts,  49 
Third  eyelid,  12 
Tissue,  episcleral,  15,  27 
Toxic  amblyopia,  134 
treatment  of,  135 
Trachoma,  37,  72,  74,  75,  97 
Traumatic  cataract,  138 
Tremulous  iris,  21,  31 
Trichiasis,  36,  43 

operation  for,  53,  54 

treatment  of,  43 
Trichinosis,  Hds  in,  30 
Tuberculosis  of  conjunctiva,  79 

of  lids,  37 

of  iris,  120 
Tumors  of  ciliary  body,  121,  122 

of  conjunctiva,  84-86 

of  iris,  119,  121,  122 

of  lids,  41 
Turbid  aqueous  humor,  30 

vitreous,  30,  31 

Ulcers  of  cornea,  71,  82,  90-93 
causes,  91 


2IO 


INDEX 


Ulcers  of  cornea,  treatment,  93 

of  lids,  42 
Uvea,  17,  26 
Uveal  tract,  17,  93 

Vessels,  retinal,  20 
Virtual  focus,  184 

image,  183 
Vision,  acuity  of,  187 

fields  of,  192 

principles  of,  181 
Vitreous,  14,  26,  31 


Vitreous,  fluid,  27,  32 
turbid,  30,  31 

Washes,  antiseptic,  for  eye,  200 
Wounds  of  ciliary  region,  115 

of  lids,  36 

perforating,  of  cornea,  166 

Xerosis  of  conjimctiva,  75 
of  cornea,  102 

ZiNN,  zonule  of,  26 


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biochemic  tests,  culture  media,  isolation  of  cultures,  the  manufacture 
of  the  various  toxins,  antitoxins,  tuberculins,  and  vaccines. 
B.  F.  Kaupp,  D.  V.  S.,  State  Agricultural  College,  Fort  Collins:  "It  is 
the  best  in  print  on  the  subject.  What  pleases  me  most  is  that  it  con- 
tains all  the  late  results  of  research." 

Si§s®ini^s   Vdtdiriffiiairy    Aimatoinniy 

I'etfrinary  Anutoiiiy.  By  Septimus  Sisson,  S.  B.,  V.  S.,  Pro- 
fessor of  Comparative  Anatomy,  Ohio  State  University.  Octavo 
of  826  pages,  588  illustrations.       Cloth,  ^7.00  net.      The  Standard. 

Here  is  a  work  of  the  greatest  usefulness  in  the  study  and  pursuit  of 
the  veterinary  sciences.  This  is  a  clear  and  concise  statement  of  the 
structure  of  the  principal  domesticated  animals— an  exhaustive  gross 
anatomy  of  the  horse,  ox,  pig,  and  dog,  including  the  splanchnology  of 
the  sheep,  presented  in  a  form  never  before  approached  for  practical 
usefulness. 

Prof.  E.  D.  Harris,  North  Dakota  Agricultural  College:  "  It  is  the  best 
of  its  kind  in  the  English  language.     It  is  quite  free  from  errors." 

Skairp's  Veteirmiiiry  OiplkitKalinni©l©gy 

Veterinary  Ophthalmology.  By  Walter  N.  Sharp,  M.  D., 
Professor  of  Ophthalmology,  Indiana  Veterinary  College.  i2mo 
of  200  pages,  illustrated.  Ready  Soon. 

This  new  work  covers  a  much  neglected  but  important  field  of  veter- 
inary practice.  Dr.  Sharp  has  presented  his  subject  in  a  concise,  crisp 
way,  so  that  you  can  pick  up  his  book  and  get  to  "  the  point "  quickly. 
He  first  gives  you  the  anatomy  of  the  eye,  then  examination,  followed 
by  the  various  diseases,  including  injuries,  parasites,  errors  of  refrac- 
tion, and  medicines  used  in  ophthalmic  therapeutics.  The  text  is 
illustrated. 


Saunders"  College  Text-Books 


FjI(b\  F<BitB@msil  Hygidin® 

Personal  Hygiene.  Edited  by  Walter  L.  Pyle,  M.  D.,  Fellow 
of  the  American  Academy  of  Medicine.  i2mo  of  515  pages,  illus- 
trated.     Cloth,  $1.50  net.  Fifth  Edition. 

Dr.  Pyle's  work  sets  forth  the  best  means  of  preventing  disease— the  best 
means  to  perfect  health.  It  tells  you  how  to  care  for  the  teeth,  skin, 
complexion,  and  hair.  It  takes  up  mouth  breathing,  catching  cold, 
care  of  the  vocal  cords,  care  of  the  eyes,  school  hygiene,  body  posture, 
ventilation,  house-cleaning,  etc.  There  are  chapters  on  food  adulter- 
ation (by  Dr.  Harvey  W.  Wiley),  domestic  hygiene,  and  home  gymnastics. 
Canadian  Teacher:  ''Such  a  complete  and  authoritative  treatise 
should  be  in  the  hands  of  every  teacher." 

Galfeiraiilk's   Ex(gir€k(g   for   W©m(aini 

Personal  Hygiene  and  Physical  Training  for  Women  By 
Anna  M.  Galbraith,  M.  D.,  Fellow  New  York  Academy  of 
Medicine.        i2mo    of  371    pages,  illustrated.       Cloth,   ^2.00  net. 

Dr.  Galbraith's  book  meets  a  need  long  existing— a  need  for  a  simple 
manual  of  personal  hygiene  and  physical  training  for  women  along  sci- 
entific lines.  There  are  chapters  on  hair,  hands  and  feet,  dress,  devel- 
opment of  the  form,  and  the  attainment  of  good  carriage  by  dancing, 
walking,  running,  swimming,  rowing,  etc. 

Dr.  Harry  B.  Boice,  Trenton  State  Normal  School:  ''It  is  intensely 
interesting  and  is  the  finest  work  of  the  kind  of  which  I  know." 

Exercise  in  Education  and  Medicine.  By  R.  Tait  McKenzie, 
M.  D.,  Professor  of  Physical  Kducation,  University  of  Pennsyl- 
vania. Octavo  of  406  pages,  whh  346  illustrations.  Cloth,  $3.50 
net.  Adopted  by  U.  S.  Army. 

Chapters  of  special  value  in  college  work  are  those  on  exercise  by  the 
different  systems:  play-grounds,  physical  education  in  school,  college, 
and  university. 

D.  A.  Sargent,  M.  D.,  Hemenway  Gymnasium:  "It  should  be  in  the 
hands  of  every  physical  educator." 


Saunders*  College  Text-Books 


Half  §  Moirinniiil  Histotegj 

Normal  Histology  and  Organography.     By  Charles  Hill,  M.  D. 
i2mo  of  468  pages,  337  illustrations.      Flexible  leather,  $2.00  net. 

Second  Edition. 

Dr.  Hill's  work  is  characterized  by  a  brevity  of  style,  yet  a  complete- 
ness of  discussion,  rarely  met  in  a  book  of  this  size.  The  entire  field 
is  covered,  beginning  with  the  preparation  of  material,  the  cell,  the 
various  tissues,  on  through  the  different  organs  and  regions,  and  end- 
ing with  fixing  and  staining  solutions. 

Dr.  E.  P.  Porterfield,  St.  Louis  University:  "  I  am  very  much  gratified 
to  find  so  handy  a  work.  It  is  so  full  and  complete  that  it  meets  all 
requirements." 


Histology.  By  A.  A.  Bohm,  M.  D.,  and  RI.  von  Davidoff, 
M.  D.,  of  Munich.  Edited  by  G.  Carl  Huber,  M.  D.,  Professor 
of  Embryology  at  the  Wistar  Institute,  University  of  Pennsyl- 
vania. Octavoof  528  pages,  377  illustrations.  Flexible  cloth,  $3.50 
net.  Second  Edition. 

This  work  is  conceded  to  be  the  most  complete  text-book  on  human 
histology  published.  Particularly  full  on  microscopic  technic  and 
staining,  it  is  especially  serviceable  in  the  laboratory.  Every  step  in 
technic  is  clearly  and  precisely  detailed.  It  is  a  work  you  can  depend 
upon  always. 

New  York  Medical  Journal:  "There  can  be  nothing  but  praise  for 
this  model  text-book  and  laboratory  guide." 

Hdiildir^s  Einnifeiry©l©gy 

Embryology.  By  J.  C.  Heisler,  M.  D,  Professor  of  Anatomy, 
Medico-Chirurgical  College  of  Philadelphia.  Octavo  of  432  pages, 
205  illustrations.     Cloth,  H3.00  net.  Third  Edition. 

A  book  of  the  greatest  teaching  value.  The  subject  is  taken  up  sys- 
tematically, treating  the  development  of  each  tissue,  each  organ,  each 
region  and  system  in  a  most  thorough  way.  There  are  frequent  allu- 
sions to  certain  facts  of  comparative  embryology. 

Journal  American  Medical  Association :  "  The  text  is  concise,  and 
yet  sufficiently  full  for  a  text-book." 


Saunders'  College  Text-Books 


Joirdiiini^i  Gdimdiral  Ea€it(iirn©l®gy 

General  Bacteriology.  By  Edwin  O.  Jordan,  Ph.  D.,  Professor 
of  Bacteriology,  University  of  Cliicago.  Octavo  of  623  pages, 
illustrated.     Cloth,  $3.00  net.  Third  Edition. 

This  work  treats  fully  of  the  bacteriology  of  plants,  milk  and  milk 
products,  dairying,  agriculture,  water,  food  preservation;  of  leather 
tanning,  vinegar  making,  tobacco  curing;  of  household  administration 
and  sanitary  engineering.  A  chapter  of  prime  importance  to  all  stu- 
dents of  botany,  horticulture,  and  agriculture  is  that  on  the  bacterial 
diseases  of  plants. 

Prof.  T.  J.  Burrill,  University  of  Illinois:  "  I  am  using  Jordan's  Bac- 
teriology for  class  work  and  am  convinced  that  it  is  the  best  text  in 
existence." 

Eyir(i^§  Bii€it(iira©l©gis  Tdckimie 

Bacteriologic  Technic.  ByJ.  W.  H.  Eyre,  M.  D.,  Bacteriologist 
to  Guy's  Hospital,  London.  Octavo  of  375  pages,  with  170  illus- 
trations.    Cloth,  ^2.50  net. 

Dr.  Eyre  gives  clearly  the  technic  for  the  bacteriologic  examination  of 
water,  sewage,  air,  soil,  milk  and  its  products,  meats,  etc.  It  is  a  work 
of  much  value  in  the  laboratory.  The  170  illustrations  are  practical 
and  serve  well  to  clarify  the  text. 

The  London  Lancet:  ''  It  is  a  work  for  all  technical  students,  whether 
of  brewing,  dairying,  or  agriculture." 

G©irkam^s   iLaIb(0)iraiL©iry    ya€ib(ari©l©gy 

Laboratory  Bacteriology.  By  Frederic  P.  Gorham,  A.  M., 
Associate  Professor  of  Biology,  Brown  University,  Providence. 
i2mo  of  192  pages,  illustrated.     Cloth,  $1.25  net. 

The  subjects  of  special  interest  to  scientific  students  are  the  identifica- 
tion of  bacteria  of  water,  milk,  air,  and  soil.  Professor  Gorham  has 
succeeded  in  making  his  instructions  clear  and  easily  grasped  by  the 
student.     The  text  is  illustrated. 

Science:  "  The  author  has  described  small  points  of  technic  usually 
left  for  the  student  to  learn  himself." 


Saunders'  College  Text-Books 


L^uisk^s  EldinriKiiffiiLs  ©f  N^itiriitiomi 

Elements  of  Nutrition.  By  Graham  Lusk,  Ph.  D.,  Professor  of 
Physiology,  Cornell  Medical  School.  Octavo  of  402  pages,  illus 
trated.     Cloth,  ^.3  00  net.  Second  Edition. 

The  clear  and  practical  presentation  of  starvation,  regulation  of  tem- 
perature, the  influence  of  protein  food,  the  specific  dynamic  action 
of  food-stuffs,  the  influence  of  fat  and  carbohydrate  ingestion  and  of 
mechanical  work  render  the  work  unusually  valuable.  It  will  prove 
extremely  helpful  to  students  of  animal  dietetics  and  of  metabolism 
generally. 

Dr.  A.  P.  Brubaker,  Jefferson  Medical  College:  "  It  is  undoubtedly  the 
best  presentation  of  the  subject  in  English.    The  work  is  indispensable." 

IHI©wdf §  Plkyii©l©gy 

Physiology.  By  William  H.  Howell,  M.  D.,  Ph.  D.,  Professor 
of  Physiology,  Johns  Hopkins  University.  Octavo  of  1018  pages, 
illustrated.     Cloth,  $4.00  net.  Fourth  Edition. 

Dr.  Howell's  work  on  human  physiology  has  been  aptly  termed  a 
"  storehouse  of  physiologic  fact  and  scientific  theory."  You  will  at 
once  be  impressed  with  the  fact  that  you  are  in  touch  with  an  expe- 
rienced teacher  and  investigator. 

Prof.  G.  H.  Caldwell,  University  of  North  Dakota:  "Of  all  the  text- 
books on  physiology  which  I  have  examined,  Howell's  is  the  best." 


Edirgdj  §  lHlygii(iini(i 

Hygiene.  By  D.  H.  Bergey,  M.  D.,  Assistant  Professor  of  Bac- 
teriology, University  of  Pennsylvania.  OctaVo  of  530  pages,  illus- 
trated.    Cloth,  $3.00  net.  Foitrth  Edition. 

Dr.  Bergey  gives  first  place  to  ventilation,  water-supply,  sewage,  indus- 
trial and  school  hygiene,  etc.  His  long  experience  in  teaching  this  sub- 
ject has  made  him  familiar  with  teaching  needs. 

J.  N.  Hurty,  M.  D.,  Indiana  University:  ''It  is  one  of  the  best  books 
with  which  I  am  acquainted." 


Saunders'  College  Text-Books 


®irir©w^§  Car®  ©f  IiniJ'Mirdd 

Immediate  Care  of  the  Injured.  By  Albert  S.  Morrow,  M.  D., 
Adjunct  Professor  of  Surgery,  New  York  Polyclinic.  Octavo  of 
340  pages,  238  illustrations.     Cloth,  ^^2.50  net. 

Dr.  Morrow's  book  tells  you  /w5/  what  to  do  in  any  emergency,  and  it 
is  illustrated  in  such  a  practical  way  that  the  idea  is  caught  at  once. 
There  are  chapters  on  bandaging,  practical  remedies,  first-aid  outfit, 
hypodermic  injections,  antiseptics  and  disinfectants,  accidents  and 
emergencies,  hemorrhages,  inflammation,  contusions  and  wounds,  burns 
and  scalds,  the  injurious  effects  of  cold,  fractures  and  dislocations, 
sprains,  removal  of  foreign  bodies  from  the  eye,  ear,  nose,  etc.,  poisons, 
and  their  antidotes.  There  is  no  book  better  adapted  to  first-aid  class 
work. 

Health :  "  Here  is  a  book  that  should  find  a  place  in  every  workshop 
and  factory  and  should  be  made  a  text-book  in  our  schools." 

D®irlaim(dl^§  MlMsitiraiLddl  K€{Ln®imiiir  j 

American  Illustrated  Medical  Dictionary.  By  W.  A.  Newman 
Borland,  M.  D.,  Member  of  Committee  on  Nomenclature  and 
Classification  of  Diseases,  American  Medical  Association.  Octavo 
of  986  pages,  with  323  illustrations,  119  in  colors.  Flexible 
leather,  ^4.50  net ;  thumb  indexed,  $5.00  net.  Sixth  Edition- 

If  you  want  an  unabridged  medical  dictionary,  this  is  the  one  you 
want.  It  is  down  to  the  minute;  its  definitions  are  concise,  yet  accu- 
rate and  clear;  it  is  extremely  easy  to  consult;  it  defines  all  the  newest 
terms  in  medicine  and  the  allied  subjects;  it  is  profusely  illustrated. 
This  new  edition  alone  defines  over  jooo  new  terms  not  defined  in  any 
other  medical  dictionary — bar  none.  There  is  no  other  medical  dic- 
tionary that  will  meet  your  needs  as  well  as  "Borland."  Why  not 
then  get  the  best—"  Borland  "  ? 

John  B.  Murphy,  M.  D.,  Northwestern  University:  "  It  is  unquestion- 
ably the  best  lexicon  on  medical  topics  in  the  English  language,  and, 
with  all  that,  it  is  so  compact  for  ready  reference." 

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